US BioEnergy Corporation

“time of purchase.” Electronic transfer of the Firm Shares shall be made to you at the time of purchase in such names and in such denominations as you shall specify.

          Payment of the purchase price for the Additional Shares shall be made at the additional time of purchase in the same manner and at the same office as the payment for the Firm Shares. Electronic transfer of the Additional Shares shall be made to you at the additional time of purchase in such names and in such denominations as you shall specify.

          Deliveries of the documents described in Section 6 hereof with respect to the purchase of the Shares shall be made at the offices of Sidley Austin LLP at One South Dearborn Street, Chicago, Illinois 60603 at 9:00 A.M., New York City time, on the date of the closing of the purchase of the Firm Shares or the Additional Shares, as the case may be.

     3. Representations and Warranties of the Company. The Company represents and warrants to and agrees with each of the Underwriters that:

     (a) the Registration Statement has been declared effective under the Act or, with respect to any registration statement to be filed to register the offer and sale of Shares pursuant to Rule 462(b) under the Act, will be filed with the Commission and become effective under the Act no later than 10:00 P.M., New York City time, on the date of determination of the public offering price for the Shares; no stop order of the Commission preventing or suspending the use of any Preliminary Prospectus or Permitted Free Writing Prospectus, or the effectiveness of the Registration Statement, has been issued, and no proceedings for such purpose have been instituted or, to the Company’s knowledge, are contemplated by the Commission; the Exchange Act Registration Statement has become effective as provided in Section 12 of the Exchange Act;

     (b) the Registration Statement complied when it became effective, complies as of the date hereof and, as amended or supplemented, at the time of purchase, each additional time of purchase, if any, and at all times during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, will comply, in all material respects, with the requirements of the Act; the Registration Statement did not, as of the Effective Time, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; each Preliminary Prospectus complied, at the time it was filed with the Commission, and complies as of the date hereof, in all material respects with the requirements of the Act; at no time during the period that begins on the earlier of the date of such Preliminary Prospectus and the date such Preliminary Prospectus was filed with the Commission and ends at the time of purchase did or will any Preliminary Prospectus, as then amended or supplemented, include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, and at no time during such period did or will any Preliminary Prospectus, as then amended or supplemented, together with any combination of one or more of the then issued Permitted Free Writing

Prospectuses, if any, include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; the Prospectus will comply, as of its date, the date that it is filed with the Commission, the time of purchase, each additional time of purchase, if any, and at all times during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, in all material respects, with the requirements of the Act (including, without limitation, Section 10(a) of the Act); at no time during the period that begins on the earlier of the date of the Prospectus and the date the Prospectus is filed with the Commission and ends at the later of the time of purchase, the latest additional time of purchase, if any, and the end of the period during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares did or will the Prospectus, as then amended or supplemented, include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; at no time during the period that begins on the date of such Permitted Free Writing Prospectus and ends at the time of purchase did or will any Permitted Free Writing Prospectus include an untrue statement of a material fact or, together with the Disclosure Package, omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that the Company makes no representation or warranty with respect to any statement contained in the Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus in reliance upon and in conformity with information concerning an Underwriter and furnished in writing by or on behalf of such Underwriter through you to the Company expressly for use in the Registration Statement, such Preliminary Prospectus, the Prospectus or such Permitted Free Writing Prospectus;

     (c) prior to the execution of this Agreement, the Company has not, directly or indirectly, offered or sold any Shares by means of any “prospectus” (within the meaning of the Act) or used any “prospectus” (within the meaning of the Act) in connection with the offer or sale of the Shares, in each case other than the Preliminary Prospectuses and the Permitted Free Writing Prospectuses, if any; the Company has not, directly or indirectly, prepared, used or referred to any Permitted Free Writing Prospectus except in compliance with Rules 164 and 433 under the Act; assuming that such Permitted Free Writing Prospectus is accompanied or preceded by the most recent Preliminary Prospectus that contains a price range or the Prospectus, as the case may be, and that such Permitted Free Writing Prospectus is so sent or given after the Registration Statement was filed with the Commission (and after such Permitted Free Writing Prospectus was, if required pursuant to Rule 433(d) under the Act, filed with the Commission), the sending or giving, by any Underwriter, of any Permitted Free Writing Prospectus will satisfy the provisions of Rule 164 and Rule 433 (without reliance on subsections (b), (c) and (d) of Rule 164); the Preliminary Prospectus dated November 29, 2006 is a prospectus that, other than by reason of Rule 433 or Rule 431 under the Act, satisfies the requirements of Section 10 of the Act, including a price range where required by rule; neither the

Company nor the Underwriters are disqualified, by reason of subsection (f) or (g) of Rule 164 under the Act, from using, in connection with the offer and sale of the Shares, “free writing prospectuses” (as defined in Rule 405 under the Act) pursuant to Rules 164 and 433 under the Act; the Company is not an “ineligible issuer” (as defined in Rule 405 under the Act) as of the eligibility determination date for purposes of Rules 164 and 433 under the Act with respect to the offering of the Shares contemplated by the Registration Statement; the parties hereto agree and understand that the content of any and all “road shows” (as defined in Rule 433 under the Act) related to the offering of the Shares contemplated hereby is solely the property of the Company; the Company has caused there to be made available at least one version of a “bona fide electronic road show” (as defined in Rule 433 under the Act) in a manner that, pursuant to Rule 433(d)(8)(ii) under the Act, causes the Company not to be required, pursuant to Rule 433(d) under the Act, to file, with the Commission, any Electronic Road Show;

      (d) as of the date of this Agreement, the Company has an authorized and outstanding capitalization as set forth in the sections of the Registration Statement, the Preliminary Prospectuses and the Prospectus entitled “Capitalization” and “Description of capital stock” (and any similar sections or information, if any, contained in any Permitted Free Writing Prospectus), and, as of the time of purchase and any additional time of purchase, as the case may be, the Company shall have an authorized and outstanding capitalization as set forth in the sections of the Registration Statement and the Prospectus entitled “Capitalization” and “Description of capital stock” (and any similar sections or information, if any, contained in any Permitted Free Writing Prospectus) (subject, in each case, to the issuance of shares of Common Stock upon exercise of stock options and warrants disclosed as outstanding in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus and the grant of options under existing equity incentive plans described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus); all of the issued and outstanding shares of capital stock, including the Common Stock, of the Company have been duly authorized and validly issued and are fully paid and non-assessable, have been issued in compliance with all applicable securities laws and were not issued in violation of any preemptive right, resale right, right of first refusal or similar right; prior to the date hereof, the Company has duly effected and completed a one-for-four reverse stock split of the Common Stock in the manner described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus; and the Amended and Restated Articles of Incorporation of the Company and the Amended and Restated Bylaws of the Company, each in the form filed as an exhibit to the Registration Statement, have been heretofore duly authorized and approved in accordance with the South Dakota Business Corporation Act and shall become effective and in full force and effect at or before the time of purchase; the Shares are duly listed, and admitted and authorized for trading, subject to official notice of issuance and evidence of satisfactory distribution, on the NASDAQ;

     (e) the Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of South Dakota, with full corporate power and authority to own, lease and operate its properties and conduct its

business as described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, to execute and deliver this Agreement and to issue, sell and deliver the Shares to be sold by it pursuant hereto as contemplated herein;

     (f) the Company is duly qualified to do business as a foreign corporation and is in good standing in each jurisdiction where the ownership or leasing of its properties or the conduct of its business requires such qualification, except where the failure to be so qualified and in good standing would not, individually or in the aggregate, have a material adverse effect on the business, properties, financial condition, results of operations or prospects of the Company and the Subsidiaries (as defined below) taken as a whole (the occurrence of any such effect being herein referred to as a “Material Adverse Effect”);

     (g) the Company has no subsidiaries (as defined under the Act) other than those set forth on Exhibit 21.1 to the Registration Statement (each a “Subsidiary” and, collectively, the “Subsidiaries”); the Company directly or indirectly owns all of the issued and outstanding capital stock or other equity interests of each of the Subsidiaries, except as disclosed in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus; other than the capital stock or other equity interests of the Subsidiaries, the Company does not own, directly or indirectly, any shares of stock or any other equity interests or long-term debt securities of any corporation, firm, partnership, joint venture, association or other entity; complete and correct copies of the charter and the bylaws (or similar organizational documents) of the Company and each Subsidiary and all amendments thereto have been delivered to you, and, except as set forth in the exhibits to the Registration Statement, no changes therein will be made on or after the date hereof through and including the time of purchase or, if later, any additional time of purchase; each Subsidiary has been duly incorporated or formed and is validly existing as a corporation, limited liability company, partnership or other entity in good standing under the laws of the jurisdiction of its incorporation or formation, with full corporate or other power and authority to own, lease and operate its properties and to conduct its business as described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any; each Subsidiary is duly qualified to do business and is in good standing in each jurisdiction where the ownership or leasing of its properties or the conduct of its business requires such qualification, except where the failure to be so qualified and in good standing would not, individually or in the aggregate, have a Material Adverse Effect; all of the outstanding shares of capital stock or other equity interests of each of the Subsidiaries have been duly authorized and validly issued, are fully paid and non-assessable, have been issued in compliance with all applicable securities laws, were not issued in violation of any preemptive right, resale right, right of first refusal or similar right and, except as disclosed in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus, are owned by the Company subject to no security interest, other encumbrance or adverse claims; and no options, warrants or other rights to purchase, agreements or other obligations to issue or other rights to convert any obligation into shares of capital stock or ownership interests in the Subsidiaries are

outstanding;

     (h) the Shares have been duly and validly authorized and, when issued and delivered against payment therefor as provided herein, will be duly and validly issued, fully paid and non-assessable and free of statutory and contractual preemptive rights, resale rights, rights of first refusal and similar rights; the Shares, when issued and delivered against payment therefor as provided herein, will be free of any restriction upon the voting or transfer thereof pursuant to the Company’s charter or bylaws or any agreement or other instrument to which the Company is a party;

     (i) the capital stock of the Company, including the Shares, conforms in all material respects to each description thereof, if any, contained in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any; and the certificates for the Shares are in due and proper form;

     (j) this Agreement has been duly authorized, executed and delivered by the Company;

     (k) neither the Company nor any of the Subsidiaries is in breach or violation of or in default under (nor has any event occurred which, with notice, lapse of time or both, would result in any breach or violation of, constitute a default under or give the holder of any indebtedness (or a person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a part of such indebtedness under) (A) its charter or bylaws, or (B) any indenture, mortgage, deed of trust, bank loan or credit agreement or other evidence of indebtedness, or any license, lease, contract or other agreement or instrument to which it is a party or by which it or any of its properties may be bound or affected, or (C) any federal, state, local or foreign law, regulation or rule applicable to the Company or any of the Subsidiaries or any of their respective properties, or (D) any rule or regulation of any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, the rules and regulations of the NASDAQ) having jurisdiction over the Company or any of the Subsidiaries or any of their respective properties, or (E) any decree, judgment or order applicable to it or any of its properties, except with respect to clause (B), where such breach, violation or default would not, individually or in the aggregate, have a Material Adverse Effect;

     (l) the execution, delivery and performance of this Agreement by the Company, the issuance and sale of the Shares and the consummation by the Company of the transactions contemplated hereby will not conflict with, result in any breach or violation of or constitute a default under (nor constitute any event which, with notice, lapse of time or both, would result in any breach or violation of, constitute a default under or give the holder of any indebtedness (or a person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a part of such indebtedness under) (or result in the creation or imposition of a lien, charge or encumbrance on any property or assets of the Company or any Subsidiary pursuant to) (A) the charter or bylaws of the Company or any of the Subsidiaries, or (B) any

indenture, mortgage, deed of trust, bank loan or credit agreement or other evidence of indebtedness, or any license, lease, contract or other agreement or instrument to which the Company or any of the Subsidiaries is a party or by which any of them or any of their respective properties may be bound or affected, or (C) any federal, state, local or foreign law, regulation or rule applicable to the Company or any of the Subsidiaries or any of their respective properties, or (D) any rule or regulation of any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, the rules and regulations of the NASDAQ) having jurisdiction over the Company or any of the Subsidiaries or any of their respective properties, or (E) any decree, judgment or order applicable to the Company or any of the Subsidiaries or any of their respective properties, except with respect to clause (B), where such breach, violation or default would not, individually or in the aggregate, have a Material Adverse Effect;

     (m) no approval, authorization, consent or order of or filing with any federal, state, local or foreign governmental or regulatory commission, board, body, authority or agency, or of or with any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, the NASDAQ), or approval of the shareholders of the Company, is required to be obtained or made by the Company in connection with the issuance and sale of the Shares or the consummation by the Company of the transactions contemplated hereby, other than (i) the registration of the Shares under the Act and the registration of the Common Stock under the Exchange Act, each of which has been effected (or, with respect to any registration statement to be filed hereunder pursuant to Rule 462(b) under the Act, will be effected in accordance herewith), (ii) the filing of the Amended and Restated Articles of Incorporation, which will be effected at or prior to the time of purchase, (iii) any necessary qualification under the securities or blue sky laws of the various jurisdictions in which the Shares are being offered by the Underwriters, (iv) under the Conduct Rules of the NASD or (v) the listing of the Shares on the NASDAQ;

     (n) except as described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus, (i) no person has the right, contractual or otherwise, to cause the Company to issue or sell to it any shares of Common Stock or shares of any other capital stock or other equity interests of the Company, (ii) no person has any preemptive rights, resale rights, rights of first refusal or other rights to purchase from the Company any shares of Common Stock or shares of any other capital stock of or other equity interests in the Company, (iii) no person has the right to act as an underwriter or as a financial advisor to the Company in connection with the offer and sale of the Shares and (iv) no person has the right, contractual or otherwise, to cause the Company to register under the Act any shares of Common Stock or shares of any other capital stock of or other equity interests in the Company, or to include any such shares or interests in the Registration Statement or the offering contemplated thereby;

     (o) except as described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus, (i) each of the Company and the Subsidiaries has all necessary licenses, authorizations, consents and approvals and has made all necessary filings required under any applicable law, regulation or rule, and has

obtained all necessary licenses, authorizations, consents and approvals from other persons, in order to conduct their respective businesses as presently conducted and (ii) neither the Company nor any of the Subsidiaries is in violation of, or in default under, or has received notice of any proceedings relating to revocation or modification of, any such license, authorization, consent or approval or any federal, state, local or foreign law, regulation or rule or any decree, order or judgment applicable to the Company or any of the Subsidiaries, except, with respect to clauses (i) and (ii), as would not, individually or in the aggregate, have a Material Adverse Effect;

     (p) except as described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus, there are no actions, suits, claims, investigations or proceedings pending or, to the Company’s knowledge, threatened or contemplated to which the Company or any of the Subsidiaries or, to the Company’s knowledge, any of their respective directors or officers, in their capacities as such, is or would be a party or of which any properties of the Company or any Subsidiary is or would be subject at law or in equity, before or by any federal, state, local or foreign governmental or regulatory commission, board, body, authority or agency, or before or by any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, the NASDAQ) applicable to it, except any such action, suit, claim, investigation or proceeding which, if resolved adversely to the Company or any Subsidiary, would not, individually or in the aggregate, have a Material Adverse Effect;

     (q) (i) McGladrey & Pullen LLP, whose report on the consolidated financial statements of the Company and the Subsidiaries is included in the Registration Statement, the Preliminary Prospectuses and the Prospectus [identify any Permitted Free Writing Prospectuses containing an audit report], are independent registered public accountants as required by the Act and by the rules of the Public Company Accounting Oversight Board; (ii) Christianson & Associates, whose report on the consolidated financial statements of Superior Corn Products, LLC for the periods prior to its acquisition by the Company is included in the Registration Statement, the Preliminary Prospectuses and the Prospectus [identify any Permitted Free Writing Prospectuses containing an audit report], are independent accountants as required by the Act and by the rules of the American Institute of Certified Public Accountants; and (iii) Kennedy & Coe, whose reports on the consolidated financial statements of ICM Marketing, Inc. and United Bio Energy, LLC, for the periods prior to its acquisition by the Company, are included in the Registration Statement, the Preliminary Prospectuses and the Prospectus [identify any Permitted Free Writing Prospectuses containing an audit report], are independent accountants as required by the Act and by the rules of the American Institute of Certified Public Accountants;

     (r) the historical financial statements included in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, together with the related notes and schedules, present fairly in all material respects the consolidated financial position of the Company and of United Bio Energy, LLC, Platte Valley Fuel Ethanol, LLC, Superior Corn Products, LLC and ICM Marketing, Inc., as applicable, as of the dates indicated and the consolidated results of

operations, cash flows and changes in shareholders’ equity of the Company and of United Bio Energy, LLC, Platte Valley Fuel Ethanol, LLC, Superior Corn Products, LLC and ICM Marketing, Inc., as applicable, for the periods specified and have been prepared in compliance in all material respects with the requirements of the Act and in conformity with U.S. generally accepted accounting principles applied on a consistent basis during the periods involved (except as disclosed therein); all pro forma financial statements or data included in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, comply in all material respects with the requirements of the Act, and the assumptions used in the preparation of such pro forma financial statements and data are reasonable, the pro forma adjustments used therein are appropriate to give effect to the transactions or circumstances described therein and the pro forma adjustments have been properly applied to the historical amounts in the compilation of those statements and data; the other financial and statistical data contained in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, are accurately presented and prepared on a basis consistent with the financial statements and books and records of the Company; there are no financial statements (historical or pro forma) that are required to be included in the Registration Statement, any Preliminary Prospectus or the Prospectus that are not included as required; the Company and the Subsidiaries do not have any material liabilities or obligations, direct or contingent (including any off-balance sheet obligations), not described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus; and all disclosures contained in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, regarding “non-GAAP financial measures” (as such term is defined by the rules and regulations of the Commission), if any, comply with Regulation G of the Exchange Act and Item 10 of Regulation S-K under the Act, to the extent applicable;

     (s) subsequent to the respective dates as of which information is given in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, except as disclosed therein, in each case excluding any amendments or supplements to the foregoing made after the execution of this Agreement, (i) there has not been any material adverse change, or any development involving a prospective material adverse change, in the business, properties, management, financial condition or results of operations of the Company and the Subsidiaries taken as a whole, (ii) there has not been any transaction which is material to the Company and the Subsidiaries taken as a whole, (iii) neither the Company nor any Subsidiary has incurred any obligation or liability, direct or contingent (including any off-balance sheet obligations), which is material to the Company and the Subsidiaries taken as a whole, (iv) there has not been any change in the capital stock or outstanding long-term debt of the Company or any Subsidiaries and (v) there has not been any dividend or distribution of any kind declared, paid or made on the capital stock of the Company;

     (t) the Company has obtained for the benefit of the Underwriters the agreement (a “Lock-Up Agreement”), in the form set forth as Exhibit A hereto and with such deviations therefrom for particular agreements as submitted to and approved by the

Managing Underwriters, of (i) each of its directors and “officers” (within the meaning of Rule 16a-1(f) under the Exchange Act); (ii) except as otherwise agreed to by the Managing Underwriters, each security holder of record of the Company holding in the aggregate at least 400,000 shares of Common Stock (treating, for purposes of this Section 3(t), each holder of any security convertible into or exercisable or exchangeable for shares of Common Stock or any warrant or other right to acquire shares of Common Stock or any such security as a holder of the shares of Common Stock underlying such security, warrant or right); (iii) except as otherwise agreed to by the Managing Underwriters, each security holder of record that purchased shares of Common Stock from the Company and agreed in connection therewith to execute an agreement of a type contemplated by the Lock-Up Agreement; and (iv) each Directed Share Participant that is expected to purchase at least $100,000 of Reserved Shares;

     (u) neither the Company nor any Subsidiary is, and at no time during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares will either of them be, and, after giving effect to the offering and sale of the Shares, neither of them will be, an “investment company” “or an entity “controlled” by an “investment company,” as such terms are defined in the Investment Company Act of 1940, as amended;

     (v) the Company and each of the Subsidiaries have good title to all property (real and personal) described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, as being owned by any of them, except as disclosed in the Registration Statement (excluding the exhibits thereto), the Preliminary Prospectuses and the Prospectus or as would not materially and adversely affect the value of such property, free and clear of all liens, claims, security interests or other encumbrances; all the property described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, as being held under lease by the Company or a Subsidiary is held thereby under valid, subsisting and enforceable leases;

     (w) each of the Company and the Subsidiaries owns or possesses all inventions, patent applications, patents, trademarks (both registered and unregistered), tradenames, copyrights, trade secrets and other proprietary information described in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, as being owned or licensed by it or which is necessary for the conduct of, or material to, its businesses (collectively, the “Intellectual Property”), and the Company is unaware of any claim to the contrary or any challenge by any other person to the rights of the Company or any of the Subsidiaries with respect to the Intellectual Property. To the Company’s knowledge, neither the Company nor any of the Subsidiaries has infringed or is infringing the intellectual property of a third party; neither the Company nor any Subsidiary has received notice of a claim by a third party to the contrary;

     (x) neither the Company nor any of the Subsidiaries is engaged in any unfair

labor practice; except for matters which would not, individually or in the aggregate, have a Material Adverse Effect, (i) there is (A) no unfair labor practice complaint pending or, to the Company’s knowledge, threatened against the Company or any of the Subsidiaries before the National Labor Relations Board, and no grievance or arbitration proceeding arising out of or under collective bargaining agreements is pending or, to the Company’s knowledge, threatened, (B) no strike, labor dispute, slowdown or stoppage pending or, to the Company’s knowledge, threatened against the Company or any of the Subsidiaries and (C) no union representation dispute currently existing concerning the employees of the Company or any of the Subsidiaries, (ii) to the Company’s knowledge, no union organizing activities are currently taking place concerning the employees of the Company or any of the Subsidiaries and (iii) there has been no violation of any federal, state, local or foreign law relating to discrimination in the hiring, promotion or pay of employees, any applicable wage or hour laws or any provision of the Employee Retirement Income Security Act of 1974, as amended, or the rules and regulations promulgated thereunder concerning the employees of the Company or any of the Subsidiaries;

     (y) the Company and the Subsidiaries and their respective properties, assets and operations are in compliance with, and the Company and each of the Subsidiaries hold all permits, authorizations and approvals required under, Environmental Laws (as defined below), except to the extent that failure to so comply or to hold such permits, authorizations or approvals would not, individually or in the aggregate, have a Material Adverse Effect; there are no past, present or, to the Company’s knowledge, reasonably anticipated future events, conditions, circumstances, activities, practices, actions, omissions or plans that would reasonably be expected to give rise to any material costs or liabilities to the Company or any Subsidiary under, or to interfere with or prevent compliance in all material respects by the Company or any Subsidiary with, Environmental Laws; except as would not, individually or in the aggregate, have a Material Adverse Effect, neither the Company nor any of the Subsidiaries (i) is the subject of any investigation, (ii) has received any notice or claim, (iii) is a party to or affected by any pending or, to the Company’s knowledge, threatened action, suit or proceeding, (iv) is bound by any judgment, decree or order or (v) has entered into any agreement, in each case relating to any alleged violation of any Environmental Law or any actual or alleged release or threatened release or cleanup at any location of any Hazardous Materials (as defined below) (as used herein, “Environmental Law” means any federal, state, local or foreign law, statute, ordinance, rule, regulation, order, decree, judgment, injunction, permit, license, authorization or other binding requirement, or common law, relating to health, safety or the protection, cleanup or restoration of the environment or natural resources, including those relating to the distribution, processing, generation, treatment, storage, disposal, transportation, other handling or release or threatened release of Hazardous Materials, and “Hazardous Materials” means any material (including, without limitation, pollutants, contaminants, hazardous or toxic substances or wastes) that is regulated by or may give rise to liability under any Environmental Law);

     (z) in the ordinary course of their business, the Company evaluates the effect of the Environmental Laws on the businesses, operations and properties of the Company

and its Subsidiaries, in the course of which they identify and evaluate associated costs and liabilities (including, without limitation, any capital or operating expenditures required for cleanup, closure of properties or compliance with the Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties);

     (aa) except as would not individually or in the aggregate have a Material Adverse Effect, all tax returns required to be filed by the Company or any of the Subsidiaries have been timely filed, and all taxes and other assessments of a similar nature (whether imposed directly or through withholding) including any interest, additions to tax or penalties applicable thereto due or claimed in writing to be due from such entities have been timely paid, other than those being contested in good faith and for which adequate reserves have been provided;

     (bb) the Company and each of the Subsidiaries maintain insurance covering their respective properties, operations, personnel and businesses as the Company reasonably deems adequate; such insurance insures against such losses and risks to an extent which is adequate in accordance with customary industry practice to protect the Company and the Subsidiaries and their respective businesses; all such insurance is fully in force on the date hereof and will be fully in force at the time of purchase and each additional time of purchase, if any;

     (cc) neither the Company nor any Subsidiary has sent or received any communication regarding termination of, or intent not to renew, any of the contracts or agreements referred to or described in any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus, or referred to or described in, or filed as an exhibit to, the Registration Statement, and no such termination or non-renewal has been threatened in writing by the Company or any Subsidiary or, to the Company’s knowledge, any other party to any such contract or agreement;

     (dd) the Company maintains a system of internal accounting controls sufficient to provide reasonable assurance with respect to the Company and the Subsidiaries that (i) transactions are executed in accordance with management’s general or specific authorization; (ii) transactions are recorded as necessary to permit preparation of consolidated financial statements in conformity with generally accepted accounting principles and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences;

     (ee) the Company has established and maintains “disclosure controls and procedures” (as such term is defined in Rule 13a-15 and 15d-15 under the Exchange Act) and “internal control over financial reporting” (as such term is defined in Rule 13a-15 and 15d-15 under the Exchange Act); such disclosure controls and procedures are designed to ensure that material information relating to the Company, including its consolidated subsidiaries, is made known to the Company’s Chief Executive Officer and

its Chief Financial Officer by others within those entities, and such disclosure controls and procedures are effective to perform the functions for which they were designed; in connection with the preparation of the Company’s most recent consolidated financial statements, the Company’s independent auditors and the Audit Committee of the Board of Directors of the Company have been advised of: (i) all significant deficiencies and material weaknesses, if any, in the design or operation of internal controls which could adversely affect the Company’s ability to record, process, summarize and report financial data; and (ii) all fraud, if any, whether or not material, that involves management or other employees who have a role in the Company’s internal controls; all material weaknesses, if any, in internal controls have been identified to the Company’s independent auditors; and the Company has taken all necessary actions to ensure that, upon and at all times after the filing of the Registration Statement, the Company and the Subsidiaries and their respective officers and directors, in their capacities as such, will be in compliance in all material respects with the applicable provisions of the Sarbanes-Oxley Act of 2002 (the “Sarbanes-Oxley Act”) and the rules and regulations promulgated thereunder;

     (ff) each “forward-looking statement” (within the meaning of Section 27A of the Act or Section 21E of the Exchange Act) contained in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, has been made or reaffirmed with a reasonable basis and in good faith;

     (gg) all statistical or market-related data included in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, are based on or derived from sources that the Company reasonably believes to be reliable and accurate, and the Company has obtained the written consent to the use of such data from such sources to the extent required;

     (hh) neither the Company nor any of the Subsidiaries nor, to the Company’s knowledge, any employee or agent of the Company or any Subsidiary has made any payment of funds of the Company or any Subsidiary or received or retained any funds in violation of any law, rule or regulation (including, without limitation, the Foreign Corrupt Practices Act of 1977), which payment, receipt or retention of funds is of a character required to be disclosed in the Registration Statement, any Preliminary Prospectus or the Prospectus;

     (ii) no Subsidiary is currently prohibited, directly or indirectly, from paying any dividends to the Company, from making any other distribution on such Subsidiary’s capital stock, from repaying to the Company any loans or advances to such Subsidiary from the Company or from transferring any of such Subsidiary’s property or assets to the Company or any other Subsidiary of the Company, except, in each case, as described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus;

     (jj) the issuance and sale of the Shares to the Underwriters as contemplated hereby will not cause any right to acquire any shares of preferred stock of the Company to become exercisable;

     (kk) except pursuant to this Agreement, neither the Company nor any of the Subsidiaries has incurred any liability for any finder’s or broker’s fee or agent’s commission in connection with the execution and delivery of this Agreement or the consummation of the transactions contemplated hereby or by the Registration Statement;

     (ll) neither the Company nor any of the Subsidiaries nor, to the Company’s knowledge, any of their respective directors, officers, affiliates or controlling persons has taken, directly or indirectly, any action designed, or which has constituted or might reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Shares;

     (mm) to the Company’s knowledge, there are no affiliations or associations between (i) any member of the NASD and (ii) the Company or any of the Company’s officers, directors or 5% or greater security holders or any beneficial owner of the Company’s unregistered equity securities that were acquired at any time on or after the 180th day immediately preceding the date the Registration Statement was initially filed with the Commission, except as disclosed in the Registration Statement (excluding the exhibits thereto), the Preliminary Prospectuses and the Prospectus;

     (nn) the Registration Statement, each Preliminary Prospectus, the Prospectus and each Permitted Free Writing Prospectus comply, and any further amendments or supplements thereto will comply, with any applicable laws or regulations of any foreign jurisdiction in which any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus is distributed in connection with the Directed Share Program; and no approval, authorization, consent or order of or filing with any governmental or regulatory commission, board, body, authority or agency, other than those heretofore obtained, is required in connection with the offering of the Reserved Shares in any jurisdiction where the Reserved Shares are being offered; and

     (oo) the Company has not offered, or caused the Underwriters to offer, Shares to any person pursuant to the Directed Share Program with the intent to influence unlawfully (i) a customer or supplier of the Company or any of the Subsidiaries to alter the customer’s or supplier’s level or type of business with the Company or any of the Subsidiaries, or (ii) a trade journalist or publication to write or publish favorable information about the Company or any of the Subsidiaries or any of their respective products or services.

          In addition, any certificate signed by any officer of the Company or any of the Subsidiaries and delivered to the Underwriters or counsel for the Underwriters in connection with the offering of the Shares shall be deemed to be a representation and warranty by the Company, as to matters covered thereby, to each Underwriter.

     4. Certain Covenants of the Company. The Company hereby agrees:

     (a) to furnish such information as may be required and otherwise to cooperate

in qualifying the Shares for offering and sale under the securities or blue sky laws of such states or other jurisdictions as you may reasonably designate and to maintain such qualifications in effect so long as you may reasonably request for the distribution of the Shares; provided, however, that the Company shall not be required to qualify as a foreign corporation, to subject itself to taxation in any foreign jurisdiction or to consent to the service of process under the laws of any such jurisdiction (except service of process with respect to the offering and sale of the Shares); and to promptly advise you of the receipt by the Company of any notification with respect to the suspension of the qualification of the Shares for offer or sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose;

     (b) to make available to the Underwriters in New York City, as soon as practicable after this Agreement becomes effective, and thereafter from time to time to furnish to the Underwriters, as many copies of the Prospectus (or of the Prospectus as amended or supplemented if the Company shall have made any amendments or supplements thereto after the effective date of the Registration Statement) as the Underwriters may reasonably request for the purposes contemplated by the Act; in case any Underwriter is required to deliver (whether physically or through compliance with Rule 172 under the Act or any similar rule) a prospectus after the nine-month period referred to in Section 10(a)(3) of the Act in connection with the sale of the Shares, the Company will prepare, at its expense, promptly upon request such amendment or amendments to the Registration Statement and the Prospectus as may be necessary to permit compliance with the requirements of Section 10(a)(3) of the Act;

     (c) if, at the time this Agreement is executed and delivered, it is necessary or appropriate for a post-effective amendment to the Registration Statement, or a Registration Statement under Rule 462(b) under the Act, to be filed with the Commission and become effective before the Shares may be sold, the Company will use its best efforts to cause such post-effective amendment or such Registration Statement to be filed and become effective, and will pay any applicable fees in accordance with the Act, as soon as possible; and the Company will advise you promptly and, if requested by you, will confirm such advice in writing, (i) when such post-effective amendment or such Registration Statement has become effective, and (ii) if Rule 430A under the Act is used, when the Prospectus is filed with the Commission pursuant to Rule 424(b) under the Act (which the Company agrees to file in a timely manner in accordance with such Rules);

     (d) to advise you promptly, confirming such advice in writing, of any request by the Commission for amendments or supplements to the Registration Statement, the Exchange Act Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus or for additional information with respect thereto, or of notice of institution of proceedings for, or the entry of a stop order, suspending the effectiveness of the Registration Statement and, if the Commission should enter a stop order suspending the effectiveness of the Registration Statement, to use its best efforts to obtain the lifting or removal of such order as soon as possible; to advise you promptly of any proposal to amend or supplement the Registration Statement or the Exchange Act Registration Statement, any Preliminary Prospectus or the Prospectus, and to provide you

and Underwriters’ counsel copies of any such documents for review and comment a reasonable amount of time prior to any proposed filing and to file no such amendment or supplement to which you shall reasonably object in writing;

     (e) subject to Section 4(d) hereof, to timely file all reports and documents and any preliminary or definitive proxy or information statement required to be filed by the Company with the Commission in order to comply with the Exchange Act for so long as a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares; and to provide you with a copy of such reports and statements and other documents to be filed by the Company pursuant to Section 13, 14 or 15(d) of the Exchange Act during such period a reasonable amount of time prior to any proposed filing and to promptly notify you of such filings;

     (f) to advise the Underwriters promptly of the happening of any event known to the Company within the period during which a prospectus is required by the Act to be delivered (whether physically or through compliance with Rule 172 under the Act or any similar rule) in connection with any sale of Shares, which event could require the making of any change in the Prospectus then being used so that the Prospectus would not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading, and during such time, subject to Section 4(d) hereof, to prepare and furnish, at the Company’s expense, to the Underwriters promptly such amendments or supplements to such Prospectus as may be necessary to reflect any such change;

     (g) to make generally available to its security holders, and, if not available on the Commission’s Electronic Data Gathering, Analysis, and Retrieval system, to deliver to you, an earnings statement of the Company (which will satisfy the provisions of Section 11(a) of the Act) covering a period of twelve months beginning after the effective date of the Registration Statement (as defined in Rule 158(c) under the Act) as soon as is reasonably practicable after the termination of such twelve-month period but in any case not later than March 17, 2008;

     (h) to furnish to you six copies of the Registration Statement, as initially filed with the Commission, and of all amendments thereto (including all exhibits thereto) and sufficient copies of the foregoing (other than exhibits) for distribution of a copy to each of the other Underwriters;

     (i) to furnish to you as early as practicable prior to the time of purchase and any additional time of purchase, as the case may be, but not later than two business days prior thereto, a copy of the latest available unaudited interim and monthly consolidated financial statements, if any, of the Company and the Subsidiaries which have been read by the Company’s independent registered public accountants, as stated in their letter to be furnished pursuant to Section 6(d) hereof;

     (j) to apply the net proceeds from the sale of the Shares in the manner set

forth under the caption “Use of proceeds” in the Prospectus and to file such reports with the Commission with respect to the sale of the Shares and the application of the proceeds therefrom as may be required by Rule 463 under the Act;

     (k) to pay all costs, expenses, fees and taxes in connection with (i) the preparation and filing of the Registration Statement, each Preliminary Prospectus, the Prospectus, each Permitted Free Writing Prospectus and any amendments or supplements thereto, and the printing and furnishing of copies of each thereof to the Underwriters and to dealers (including costs of mailing and shipment), (ii) the registration, issue, sale and delivery of the Shares including any stock or transfer taxes and stamp or similar duties payable upon the sale, issuance or delivery of the Shares to the Underwriters, (iii) the qualification of the Shares for offering and sale under state or foreign laws and the determination of their eligibility for investment under state or foreign law (including the reasonable legal fees and filing fees and other disbursements of counsel for the Underwriters incurred in connection with such qualifications and determinations) and the printing and furnishing of copies of any blue sky surveys or legal investment surveys to the Underwriters and to dealers, (iv) any listing of the Shares on any securities exchange or qualification of the Shares for quotation on the NASDAQ and any registration thereof under the Exchange Act, (v) any filing for review of the public offering of the Shares by the NASD, including the reasonable legal fees and filing fees and other disbursements of counsel to the Underwriters incurred in connection with such filing, (vi) the fees and disbursements of any transfer agent or registrar for the Shares, (vii) the costs and expenses of the Company relating to presentations or meetings undertaken in connection with the marketing of the offering and sale of the Shares to prospective investors and the Underwriters’ sales forces, including, without limitation, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged by the Company in connection with the road show presentations, travel, lodging and other expenses incurred by the officers of the Company and any such consultants, and the cost¹ of any aircraft chartered in connection with the road show, (viii) the costs and expenses of qualifying the Shares for inclusion in the book-entry settlement system of the DTC, (ix) the preparation and filing of the Exchange Act Registration Statement, including any amendments thereto, (x) the offer and sale of the Reserved Shares, including all costs and expenses of UBS-FinSvc and the Underwriters, including the fees and disbursement of counsel for the Underwriters and (xi) the performance of the Company’s other obligations hereunder;

     (l) to comply with Rule 433 under the Act;

     (m) beginning on the date hereof and ending on, and including, the date that is 180 days after the date hereof (the “Lock-Up Period”), without the prior written consent of UBS, not to (i) sell, offer to sell, contract or agree to sell, hypothecate, pledge, grant any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly, or establish or increase a put equivalent position or liquidate or decrease a call

equivalent position within the meaning of Section 16 of the Exchange Act and the rules and regulations of the Commission promulgated thereunder, with respect to, any Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, or any warrants or other rights to purchase Common Stock or any such securities, (ii) file or cause to become effective a registration statement under the Act relating to the offer and sale of any Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, or any warrants or other rights to purchase Common Stock or any such securities, (iii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, or any warrants or other rights to purchase Common Stock or any such securities, whether any such transaction is to be settled by delivery of Common Stock or such other securities, in cash or otherwise or (iv) publicly announce an intention to effect any transaction specified in clause (i), (ii) or (iii), except, in each case, for (A) the registration of the offer and sale of the Shares as contemplated by this Agreement, (B) issuances of Common Stock upon the exercise of options or warrants disclosed as outstanding in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus, (C) the issuance to employees or directors of restricted stock grants or stock options not vested or exercisable during the Lock-Up Period pursuant to equity incentive plans described in the Registration Statement (excluding the exhibits thereto), each Preliminary Prospectus and the Prospectus, (D) the filing of registration statements on Form S-8 relating to shares of Common Stock which may be issued pursuant to existing equity incentive plans and (E) the registration under the Act and issuance by the Company of shares of Common Stock, in an aggregate amount not to exceed 10% of the shares of Common Stock outstanding immediately following the time of purchase, in connection with any acquisitions or strategic investments by the Company or any of its Subsidiaries so long as such issuances under this clause (E) are conditioned upon the execution by the recipients of an agreement of a type contemplated by the Lock-Up Agreement; provided, however, that if (a) during the period that begins on the date that is fifteen (15) calendar days plus three (3) business days before the last day of the Lock-Up Period and ends on the last day of the Lock-Up Period, the Company issues an earnings release or material news or a material event relating to the Company occurs; or (b) prior to the expiration of the Lock-Up Period, the Company announces that it will release earnings results during the sixteen (16) day period beginning on the last day of the Lock-Up Period, then the restrictions imposed by this Section 4(m) shall continue to apply until the expiration of the date that is fifteen (15) calendar days plus three (3) business days after the date on which the issuance of the earnings release or the material news or material event occurs;

     (n) prior to the time of purchase or any additional time of purchase, as the case may be, except as required by law, to issue no press release or other communication directly or indirectly and hold no press conferences with respect to the Company or any Subsidiary, the financial condition, results of operations, business, properties, assets, or liabilities of the Company or any Subsidiary, or the offering of the Shares, without your prior consent (such consent not to be unreasonably withheld);

     (o) not, at any time at or after the execution of this Agreement, to offer or sell any Shares by means of any “prospectus” (within the meaning of the Act), or use any “prospectus” (within the meaning of the Act) in connection with the offer or sale of the Shares, in each case other than the Prospectus;

     (p) not to, and to cause the Subsidiaries not to, take, directly or indirectly, any action designed, or which will constitute, or has constituted, or might reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Shares;

     (q) to use its best efforts to cause the Common Stock to be listed for quotation on the NASDAQ and to maintain such listing;

     (r) to maintain a transfer agent and, if necessary under the jurisdiction of incorporation of the Company, a registrar for the Common Stock; and

     (s) to cause each Directed Share Participant that purchases at least $100,000 of Reserved Shares to execute a Lock-Up Agreement and otherwise to cause the Reserved Shares to be restricted from sale, transfer, assignment, pledge or hypothecation to such extent as may be required by the NASD and its rules, and to direct the transfer agent to place stop transfer restrictions upon such Reserved Shares during the Lock-Up Period or any such longer period of time as may be required by the NASD and its rules; and to comply in all material respects with all applicable securities and other applicable laws, rules and regulations in each jurisdiction in which the Reserved Shares are offered in connection with the Directed Share Program.

     5. Reimbursement of Underwriters’ Expenses. If the Shares are not delivered for any reason other than the termination of this Agreement pursuant to the fifth paragraph of Section 8 hereof or the default by one or more of the Underwriters in its or their respective obligations hereunder, the Company shall, in addition to paying the amounts described in Section 4(k) hereof, reimburse the Underwriters for all of their out-of-pocket expenses reasonably incurred, including the reasonable fees and disbursements of their counsel. Except as set forth in Section 4(k) and this Section 5, the Underwriters will bear all of their own costs and expenses, including the fees and disbursements of their counsel and any stock transfer taxes applicable to the resale of any Shares by them.

     6. Conditions of Underwriters’ Obligations. The several obligations of the Underwriters hereunder are subject to the accuracy of the representations and warranties on the part of the Company on the date hereof, at the time of purchase and, if applicable, at the additional time of purchase, the performance by the Company of its obligations hereunder and to the following additional conditions precedent:

     (a) The Company shall furnish to you at the time of purchase and, if applicable, at the additional time of purchase, an opinion and negative assurance letter from Skadden, Arps, Slate, Meagher & Flom LLP, special counsel for the Company, addressed to the Underwriters, and dated the time of purchase or the additional time of

purchase, as the case may be, with executed copies for each of the other Underwriters, in the form set forth in Exhibit B hereto.

     (b) The Company shall furnish to you at the time of purchase and, if applicable, at the additional time of purchase, an opinion of the General Counsel of the Company, addressed to the Underwriters, and dated the time of purchase or the additional time of purchase, as the case may be, with executed copies for each of the other Underwriters, in the form set forth in Exhibit C hereto.

     (c) The Company shall furnish to you at the time of purchase and, if applicable, at the additional time of purchase, an opinion of Davenport, Evans, Hurwitz & Smith, L.L.P., South Dakota counsel for the Company, addressed to the Underwriters, and dated the time of purchase or the additional time of purchase, as the case may be, with executed copies for each of the other Underwriters, in the form set forth in Exhibit D hereto.

     (d) You shall have received from McGladrey & Pullen, LLP letters dated, respectively, the date of this Agreement, the time of purchase and, if applicable, the additional time of purchase, and addressed to the Underwriters (with executed copies for each of the Underwriters) in the forms approved by the Managing Underwriters, which letters shall cover, without limitation, the various financial disclosures contained in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, other than with respect to ICM Marketing, Inc. and, for the periods prior to their respective acquisitions by the Company, Superior Corn Products, LLC and United Bio Energy, LLC.

     (e) You shall have received from Christianson & Associates letters dated, respectively, the date of this Agreement, the time of purchase and, if applicable, the additional time of purchase, and addressed to the Underwriters (with executed copies for each of the Underwriters) in the forms approved by the Managing Underwriters, which letters shall cover, without limitation, the various financial disclosures contained in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, with respect to Superior Corn Products, LLC for the periods prior to its acquisition by the Company.

     (f) You shall have received from Kennedy & Coe letters dated, respectively, the date of this Agreement, the time of purchase and, if applicable, the additional time of purchase, and addressed to the Underwriters (with executed copies for each of the Underwriters) in the forms approved by the Managing Underwriters, which letters shall cover, without limitation, the various financial disclosures contained in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, with respect to ICM Marketing, Inc. and, for the periods prior to its acquisition by the Company, United Bio Energy, LLC.

     (g) You shall have received at the time of purchase and, if applicable, at the additional time of purchase, the favorable opinion of Sidley Austin LLP, counsel for the

Underwriters, dated the time of purchase or the additional time of purchase, as the case may be, in the form set forth in Exhibit E hereto.

     (h) No Prospectus or amendment or supplement to the Registration Statement or the Prospectus shall have been filed to which you shall have reasonably objected in writing.

     (i) The Registration Statement, the Exchange Act Registration Statement and any registration statement required to be filed, prior to the sale of the Shares, under the Act pursuant to Rule 462(b) shall have been filed and shall have become effective under the Act or the Exchange Act, as the case may be. If Rule 430A under the Act is used, the Prospectus shall have been filed with the Commission pursuant to Rule 424(b) under the Act at or before 5:30 P.M., New York City time, on the second full business day after the date of this Agreement (or such earlier time as may be required under the Act).

     (j) Prior to and at the time of purchase, and, if applicable, the additional time of purchase, (i) no stop order with respect to the effectiveness of the Registration Statement shall have been issued under the Act or proceedings initiated under Section 8(d) or 8(e) of the Act; (ii) the Registration Statement and all amendments thereto shall not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; (iii) none of the Preliminary Prospectuses or the Prospectus, and no amendment or supplement thereto, shall include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading; (iv) no Disclosure Package, and no amendment or supplement thereto, shall include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading; and (v) none of the Permitted Free Writing Prospectuses, if any, shall include an untrue statement of a material fact or, together with the Disclosure Package, omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they are made, not misleading.

     (k) The Company will, at the time of purchase and, if applicable, at the additional time of purchase, deliver to you a certificate of its Chief Executive Officer and its Chief Financial Officer, dated the time of purchase or the additional time of purchase, as the case may be, in the form attached as Exhibit F hereto.

     (l) You shall have received each of the signed Lock-Up Agreements referred to in Section 3(t) hereof.

     (m) The Company shall have furnished to you such other documents and certificates as to the accuracy and completeness in all material respects of any statement in the Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus as of the time of purchase and, if applicable, the additional time of purchase, as you may reasonably request

     (n) The Shares shall have been approved for quotation on the NASDAQ, subject only to notice of issuance and evidence of satisfactory distribution at or prior to the time of purchase or the additional time of purchase, as the case may be.

     (o) The NASD shall not have raised any objection with respect to the fairness or reasonableness of the underwriting, or other arrangements of the transactions, contemplated hereby.

     7. Effective Date of Agreement; Termination. This Agreement shall become effective when the parties hereto have executed and delivered this Agreement.

          The obligations of the several Underwriters hereunder shall be subject to termination in the absolute discretion of the Managing Underwriters, if (1) since the time of execution of this Agreement or the earlier respective dates as of which information is given in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, there has been any change or any development involving a prospective change in the business, properties, management, financial condition or results of operations of the Company and the Subsidiaries taken as a whole, the effect of which change or development is, in the sole judgment of the Managing Underwriters, so material and adverse as to make it impractical or inadvisable to proceed with the public offering or the delivery of the Shares on the terms and in the manner contemplated in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, or (2) since the time of execution of this Agreement, there shall have occurred: (A) a suspension or material limitation in trading in securities generally on the NYSE, the American Stock Exchange or the NASDAQ; (B) a suspension or material limitation in trading in the Company’s securities on the NASDAQ; (C) a general moratorium on commercial banking activities declared by either federal or New York State authorities or a material disruption in commercial banking or securities settlement or clearance services in the United States; (D) an outbreak or escalation of hostilities or acts of terrorism involving the United States or a declaration by the United States of a national emergency or war; or (E) any other calamity or crisis or any change in financial, political or economic conditions in the United States or elsewhere, if the effect of any such event specified in clause (D) or (E), in the sole judgment of the Managing Underwriters, makes it impractical or inadvisable to proceed with the public offering or the delivery of the Shares on the terms and in the manner contemplated in the Registration Statement, the Preliminary Prospectuses, the Prospectus and the Permitted Free Writing Prospectuses, if any, or (3) since the time of execution of this Agreement, there shall have occurred any downgrading, or any notice or announcement shall have been given or made of: (A) any intended or potential downgrading or (B) any watch, review or possible change that does not indicate an affirmation or improvement in the rating accorded any securities of or guaranteed by the Company or any Subsidiary by any “nationally recognized statistical rating organization,” as that term is defined in Rule 436(g)(2) under the Act.

          If the Managing Underwriters elect to terminate this Agreement as provided in this Section 7, the Company and each other Underwriter shall be notified promptly in writing.

          If the sale to the Underwriters of the Shares, as contemplated by this Agreement, is not carried out by the Underwriters for any reason permitted under this Agreement, or if such sale is not carried out because the Company shall be unable to comply with any of the terms of this Agreement, the Company shall not be under any obligation or liability under this Agreement (except to the extent provided in Sections 4(k), 5 and 9 hereof), and the Underwriters shall be under no obligation or liability to the Company under this Agreement (except to the extent provided in Section 9 hereof) or to one another hereunder.

     8. Increase in Underwriters’ Commitments. Subject to Sections 6 and 7 hereof, if any Underwriter shall default in its obligation to take up and pay for the Firm Shares to be purchased by it hereunder (otherwise than for a failure of a condition set forth in Section 6 hereof or a reason sufficient to justify the termination of this Agreement under the provisions of Section 7 hereof) and if the number of Firm Shares which all Underwriters so defaulting shall have agreed but failed to take up and pay for does not exceed 10% of the total number of Firm Shares, the non-defaulting Underwriters (including the Underwriters, if any, substituted in the manner set forth below) shall take up and pay for (in addition to the aggregate number of Firm Shares they are obligated to purchase pursuant to Section 1 hereof) the number of Firm Shares agreed to be purchased by all such defaulting Underwriters, as hereinafter provided. Such Shares shall be taken up and paid for by such non-defaulting Underwriters in such amount or amounts as you may designate with the consent of each Underwriter so designated or, in the event no such designation is made, such Shares shall be taken up and paid for by all non-defaulting Underwriters pro rata in proportion to the aggregate number of Firm Shares set forth opposite the names of such non-defaulting Underwriters in Schedule A.

          Without relieving any defaulting Underwriter from its obligations hereunder, the Company agrees with the non-defaulting Underwriters that it will not sell any Firm Shares hereunder unless all of the Firm Shares are purchased by the Underwriters (or by substituted Underwriters selected by you with the approval of the Company or selected by the Company with your approval).

          If a new Underwriter or Underwriters are substituted by the Underwriters or by the Company for a defaulting Underwriter or Underwriters in accordance with the foregoing provision, the Company or you shall have the right to postpone the time of purchase for a period not exceeding five business days in order that any necessary changes in the Registration Statement and the Prospectus and other documents may be effected.

          The term “Underwriter” as used in this Agreement shall refer to and include any Underwriter substituted under this Section 8 with like effect as if such substituted Underwriter had originally been named in Schedule A hereto.

          If the aggregate number of Firm Shares which the defaulting Underwriter or Underwriters agreed to purchase exceeds 10% of the total number of Firm Shares which all Underwriters agreed to purchase hereunder, and if neither the non-defaulting Underwriters nor the Company shall make arrangements within the five business day period stated above for the purchase of all the Firm Shares which the defaulting Underwriter or Underwriters agreed to purchase hereunder, this Agreement shall terminate without further act or deed and without any

liability on the part of the Company to any Underwriter and without any liability on the part of any non-defaulting Underwriter to the Company. Nothing in this paragraph, and no action taken hereunder, shall relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

     9. Indemnity and Contribution.

     (a) The Company agrees to indemnify, defend and hold harmless each Underwriter, its partners, directors and officers, members and any person who controls any Underwriter within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, and the successors and assigns of all of the foregoing persons, from and against any loss, damage, expense, liability or claim (including the reasonable cost of investigation) which, jointly or severally, any such Underwriter or any such person may incur under the Act, the Exchange Act, the common law or otherwise, insofar as such loss, damage, expense, liability or claim arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or in the Registration Statement as amended by any post-effective amendment thereof by the Company) or arises out of or is based upon any omission or alleged omission to state a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as any such loss, damage, expense, liability or claim arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information concerning such Underwriter furnished in writing by or on behalf of such Underwriter through you to the Company expressly for use in, the Registration Statement or arises out of or is based upon any omission or alleged omission to state a material fact in the Registration Statement in connection with such information, which material fact was not contained in such information and which material fact was required to be stated in such Registration Statement or was necessary to make such information not misleading, (ii) any untrue statement or alleged untrue statement of a material fact included in any Prospectus (the term Prospectus for the purpose of this Section 9 being deemed to include any Preliminary Prospectus, the Prospectus and any amendments or supplements to the foregoing), in any Permitted Free Writing Prospectus, in any “issuer information” (as defined in Rule 433 under the Act) of the Company, which “issuer information” is required to be, or is, filed with the Commission in accordance with the terms of this Agreement, or in any Prospectus together with any combination of one or more of the Permitted Free Writing Prospectuses, if any, or arises out of or is based upon any omission or alleged omission to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, except, with respect to such Prospectus or Permitted Free Writing Prospectus, insofar as any such loss, damage, expense, liability or claim arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information concerning such Underwriter furnished in writing by or on behalf of such Underwriter through you to the Company expressly for use in, such Prospectus or Permitted Free Writing Prospectus or arises out of or is based upon any omission or alleged omission to state a material fact in such Prospectus or Permitted Free Writing Prospectus in connection with such information, which material fact was not

contained in such information and which material fact was necessary in order to make the statements in such information, in the light of the circumstances under which they were made, not misleading or (iii) the Directed Share Program, except, with respect to this clause (iii), insofar as such loss, damage, expense, liability or claim is finally judicially determined to have resulted from the gross negligence or willful misconduct of the Underwriters in conducting the Directed Share Program.

          Without limitation of and in addition to its obligations under the other paragraphs of this Section 9, the Company agrees to indemnify, defend and hold harmless UBS-FinSvc and its partners, directors and officers, members and any person who controls UBS-FinSvc within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, and the successors and assigns of all of the foregoing persons, from and against any loss, damage, expense, liability or claim (including the reasonable cost of investigation) which, jointly or severally, UBS-FinSvc or any such person may incur under the Act, the Exchange Act, the common law or otherwise, insofar as such loss, damage, expense, liability or claim (1) arises out of or is based upon (a) any of the matters referred to in clauses (i) through (iii) of the first paragraph of this Section 9(a), or (b) any untrue statement or alleged untrue statement of a material fact contained in any material prepared by or on behalf or with the consent of the Company for distribution to Directed Share Participants in connection with the Directed Share Program or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading; (2) is or was caused by the failure of any Directed Share Participant to pay for and accept delivery of Reserved Shares that the Directed Share Participant has agreed to purchase; or (3) otherwise arises out of or is based upon the Directed Share Program, provided, however, that the Company shall not be responsible under this clause (3) for any loss, damage, expense, liability or claim that is finally judicially determined to have resulted from the gross negligence or willful misconduct of UBS-FinSvc in conducting the Directed Share Program. Section 9(c) shall apply equally to any Proceeding (as defined below) brought against UBS-FinSvc or any such person in respect of which indemnity may be sought against the Company pursuant to the immediately preceding sentence, except that the Company shall be liable for the expenses of one separate counsel (in addition to any local counsel) for UBS-FinSvc and any such person, separate and in addition to counsel for the persons who may seek indemnification pursuant to the first paragraph of this Section 9(a), in any such Proceeding.

     (b) Each Underwriter severally agrees to indemnify, defend and hold harmless the Company, its directors and officers and any person who controls the Company within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, and the successors and assigns of all of the foregoing persons, from and against any loss, damage, expense, liability or claim (including the reasonable cost of investigation) which, jointly or severally, the Company or any such person may incur under the Act, the Exchange Act, the common law or otherwise, insofar as such loss, damage, expense, liability or claim arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information concerning such Underwriter furnished in writing by or on behalf of such Underwriter through you to the

Company expressly for use in, the Registration Statement (or in the Registration Statement as amended by any post-effective amendment thereof by the Company), or arises out of or is based upon any omission or alleged omission to state a material fact in such Registration Statement in connection with such information, which material fact was not contained in such information and which material fact was required to be stated in such Registration Statement or was necessary to make such information not misleading or (ii) any untrue statement or alleged untrue statement of a material fact contained in, and in conformity with information concerning such Underwriter furnished in writing by or on behalf of such Underwriter through you to the Company expressly for use in, a Prospectus or a Permitted Free Writing Prospectus, or arises out of or is based upon any omission or alleged omission to state a material fact in such Prospectus or Permitted Free Writing Prospectus in connection with such information, which material fact was not contained in such information and which material fact was necessary in order to make the statements in such information, in the light of the circumstances under which they were made, not misleading.

     (c) If any action, suit or proceeding (each, a “Proceeding”) is brought against a person (an “indemnified party”) in respect of which indemnity may be sought against the Company or an Underwriter (as applicable, the “indemnifying party”) pursuant to subsection (a) or (b), respectively, of this Section 9, such indemnified party shall promptly notify such indemnifying party in writing of the institution of such Proceeding and such indemnifying party shall assume the defense of such Proceeding, including the employment of counsel reasonably satisfactory to such indemnified party and payment of all fees and expenses of such counsel; provided, however, that the omission to so notify such indemnifying party shall not relieve such indemnifying party from any liability which such indemnifying party may have to any indemnified party or otherwise, except to the extent the indemnifying party is actually materially prejudiced thereby. The indemnified party or parties shall have the right to employ its or their own counsel in any such case, but the fees and expenses of such counsel shall be at the expense of such indemnified party or parties unless the employment of such counsel shall have been authorized in writing by the indemnifying party in connection with the defense of such Proceeding or the indemnifying party shall not have, within a reasonable period of time in light of the circumstances, employed counsel to defend such Proceeding or such indemnified party or parties shall have reasonably concluded, upon advice of counsel (which may be an internal counsel), that there may be defenses available to it or them which are different from, additional to or in conflict with those available to such indemnifying party (in which case such indemnifying party shall not have the right to direct the defense of such Proceeding on behalf of the indemnified party or parties, but the indemnifying party may employ counsel and participate in the defense thereof, at its own cost and expense), in any of which events such reasonably incurred fees and expenses shall be borne by such indemnifying party and paid as incurred (it being understood, however, that, except as provided in the second paragraph of Section 9(a), such indemnifying party shall not be liable for the expenses of more than one separate counsel (in addition to any local counsel) in any one Proceeding or series of related Proceedings in the same jurisdiction representing the indemnified parties who are parties to such Proceeding). The indemnifying party shall not be liable for any settlement of any

Proceeding effected without its written consent but, if settled with its written consent, such indemnifying party agrees to indemnify and hold harmless the indemnified party or parties from and against any loss or liability by reason of such settlement. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel as contemplated by the second sentence of this Section 9(c), then the indemnifying party agrees that it shall be liable for any settlement of any Proceeding effected without its written consent if (i) such settlement is entered into more than 60 business days after receipt by such indemnifying party of the aforesaid request, (ii) such indemnifying party shall not have fully reimbursed the indemnified party in accordance with such request for reimbursement of fees and expenses of counsel in accordance with this Agreement prior to the date of such settlement and (iii) such indemnified party shall have given the indemnifying party at least 30 days’ prior notice of its intention to settle. No indemnifying party shall, without the prior written consent of the indemnified party effect any settlement of any pending or threatened Proceeding in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such Proceeding and does not include an admission of fault or culpability or a failure to act by or on behalf of such indemnified party.

     (d) If the indemnification provided for in this Section 9 is unavailable to an indemnified party under subsections (a) and (b) of this Section 9 or insufficient to hold an indemnified party harmless in respect of any losses, damages, expenses, liabilities or claims referred to therein, then each applicable indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of such losses, damages, expenses, liabilities or claims (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Shares or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company on the one hand and of the Underwriters on the other in connection with the statements or omissions which resulted in such losses, damages, expenses, liabilities or claims, as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other shall be deemed to be in the same respective proportions as the total proceeds from the offering (net of underwriting discounts and commissions but before deducting expenses) received by the Company, and the total underwriting discounts and commissions received by the Underwriters, bear to the aggregate public offering price of the Shares. The relative fault of the Company on the one hand and of the Underwriters on the other shall be determined by reference to, among other things, whether the untrue statement or alleged untrue statement of a material fact or omission or alleged omission relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The amount paid or payable by a party as a result of the losses, damages, expenses, liabilities and claims referred to in this subsection shall be deemed to include

any legal or other fees or expenses reasonably incurred by such party in connection with investigating, preparing to defend or defending any Proceeding.

     (e) The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 9 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in subsection (d) above. Notwithstanding the provisions of this Section 9, no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Shares underwritten by such Underwriter and distributed to the public were offered to the public exceeds the amount of any damage which such Underwriter has otherwise been required to pay by reason of such untrue statement or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute pursuant to this Section 9 are several in proportion to their respective underwriting commitments and not joint.

     (f) The indemnity and contribution agreements contained in this Section 9 and the covenants, warranties and representations of the Company contained in this Agreement shall remain in full force and effect regardless of any investigation made by or on behalf of any Underwriter, its partners, directors or officers, members or any person (including each partner, officer or director of such person) who controls any Underwriter within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, or by or on behalf of the Company, its directors or officers or any person who controls the Company within the meaning of Section 15 of the Act or Section 20 of the Exchange Act, and shall survive any termination of this Agreement or the issuance and delivery of the Shares. The Company and each Underwriter agree promptly to notify each other of the commencement of any Proceeding against it and, in the case of the Company, against any of the Company’s officers or directors in connection with the issuance and sale of the Shares, or in connection with the Registration Statement, any Preliminary Prospectus, the Prospectus or any Permitted Free Writing Prospectus.

     10. Information Furnished by the Underwriters. The statements set forth in the last paragraph on the cover page of the Prospectus and the statements set forth in the second sentence of the paragraph entitled “Over-Allotment Option,” the first paragraph under the heading “Commissions and Discounts” and the paragraphs under the heading “Price Stabilizations, Short Positions” under the caption “Underwriting” in the Prospectus, only insofar as such statements relate to the amount of selling concession and reallowance or to over-allotment and stabilization activities that may be undertaken by the Underwriters, constitute the only information furnished by or on behalf of the Underwriters, as such information is referred to in Sections 3 and 9 hereof.

     11. Notices. Except as otherwise herein provided, all statements, requests, notices and agreements shall be in writing or by telegram or facsimile and, if to the Underwriters, shall be sufficient in all respects if delivered or sent to UBS Securities LLC (“UBS”), 299 Park Avenue, New York, NY 10171-0026, Attention: Syndicate Department (fax no. [___]), with a

copy to Piper Jaffray & Co., Inc., 800 Nicollet Mall, Minneapolis, Minnesota 55402, Attention: [_____] (fax no. [_____]), and, if to the Company, shall be sufficient in all respects if delivered or sent to the Company at the offices of the Company at [_____], Attention: [_____] (fax no. [_____]).

     12. Governing Law; Construction. This Agreement and any claim, counterclaim or dispute of any kind or nature whatsoever arising out of or in any way relating to this Agreement (“Claim”), directly or indirectly, shall be governed by, and construed in accordance with, the laws of the State of New York. The section headings in this Agreement have been inserted as a matter of convenience of reference and are not a part of this Agreement.

     13. Submission to Jurisdiction. Except as set forth below, no Claim may be commenced, prosecuted or continued in any court other than the courts of the State of New York located in the City and County of New York or in the United States District Court for the Southern District of New York, which courts shall have jurisdiction over the adjudication of such matters, and the Company consents to the jurisdiction of such courts and personal service with respect thereto. The Company hereby consents to personal jurisdiction, service and venue in any court in which any Claim arising out of or in any way relating to this Agreement is brought by any third party against any Underwriter or any indemnified party. Each Underwriter and the Company (on its behalf and, to the extent permitted by applicable law, on behalf of its shareholders and affiliates) waives all right to trial by jury in any action, proceeding or counterclaim (whether based upon contract, tort or otherwise) in any way arising out of or relating to this Agreement. The Company agrees that a final judgment in any such action, proceeding or counterclaim brought in any such court shall be conclusive and binding upon the Company and may be enforced in any other courts to the jurisdiction of which the Company is or may be subject, by suit upon such judgment.

     14. Parties at Interest. The Agreement herein set forth has been and is made solely for the benefit of the Underwriters and the Company and to the extent provided in Section 9 hereof the controlling persons, partners, directors, officers and members referred to in such Section, and their respective successors, assigns, heirs, personal representatives and executors and administrators. No other person, partnership, association or corporation (including a purchaser, as such purchaser, from any of the Underwriters) shall acquire or have any right under or by virtue of this Agreement.

     15. No Fiduciary Relationship. The Company hereby acknowledges that the Underwriters are acting solely as underwriters in connection with the purchase and sale of the Company’s securities. The Company further acknowledges that the Underwriters are acting pursuant to a contractual relationship created solely by this Agreement entered into on an arm’s length basis, and in no event do the parties intend that the Underwriters act or be responsible as a fiduciary to the Company, its management, stockholders or creditors or any other person in connection with any activity that the Underwriters may undertake or have undertaken in furtherance of the purchase and sale of the Company’s securities, either before or after the date hereof. The Underwriters hereby expressly disclaim any fiduciary or similar obligations to the Company, either in connection with the transactions contemplated by this Agreement or any matters leading up to such transactions, and the Company hereby confirms its understanding and agreement to that effect. The Company and the Underwriters agree that they are each

responsible for making their own independent judgments with respect to any such transactions and that any opinions or views expressed by the Underwriters to the Company regarding such transactions, including, but not limited to, any opinions or views with respect to the price or market for the Company’s securities, do not constitute advice or recommendations to the Company. The Company hereby waives and releases to the fullest extent permitted by law, any claims that the Company may have against the Underwriters with respect to any breach or alleged breach of any fiduciary or similar duty to the Company in connection with the transactions contemplated by this Agreement or any matters leading up to such transactions.

     16. Counterparts. This Agreement may be signed by the parties in one or more counterparts which together shall constitute one and the same agreement among the parties.

     17. Successors and Assigns. This Agreement shall be binding upon the Underwriters and the Company and their successors and assigns and any successor or assign of any substantial portion of the Company’s and any of the Underwriters’ respective businesses and/or assets.

     18. Miscellaneous. UBS, an indirect, wholly owned subsidiary of UBS AG, is not a bank and is separate from any affiliated bank, including any U.S. branch or agency of UBS AG. Because UBS is a separately incorporated entity, it is solely responsible for its own contractual obligations and commitments, including obligations with respect to sales and purchases of securities. Securities sold, offered or recommended by UBS are not deposits, are not insured by the Federal Deposit Insurance Corporation, are not guaranteed by a branch or agency, and are not otherwise an obligation or responsibility of a branch or agency.

[The Remainder of This Page Intentionally Left Blank; Signature Page Follows]

          If the foregoing correctly sets forth the understanding between the Company and the several Underwriters, please so indicate in the space provided below for that purpose, whereupon this Agreement and your acceptance shall constitute a binding agreement between the Company and the Underwriters, severally.

SCHEDULE A

		Number of
Underwriter		Firm Shares
UBS Securities LLC			[____]
Piper Jaffray & Co., Inc.			[____]
A.G. Edwards & Sons, Inc.			[____]
William Blair & Company, L.L.C.			[____]
Total			9,375,000

SCHEDULE B

 

EXHIBIT A

Lock-Up Agreement

___________ ___, 2006

UBS Securities LLC
Piper Jaffray & Co., Inc.
   as Managing Underwriters (“Managing Underwriters”)
c/o UBS Securities LLC
299 Park Avenue
New York, New York 10171-0026

Ladies and Gentlemen:

          This Lock-Up Agreement is being delivered to you in connection with the proposed Underwriting Agreement (the “Underwriting Agreement”) to be entered into by US BioEnergy Corporation, a South Dakota corporation (the “Company”), and you and the other underwriters named in Schedule A to the Underwriting Agreement, with respect to the public offering (the “Offering”) of common stock, $0.01 par value, of the Company (the “Common Stock”).

          In order to induce you to enter into the Underwriting Agreement, the undersigned agrees that, for a period (the “Lock-Up Period”) beginning on the date hereof and ending on, and including, the date that is 180 days after the date of the final prospectus relating to the Offering, the undersigned will not, without the prior written consent of the Managing Underwriters, (i) sell, offer to sell, contract or agree to sell, hypothecate, pledge, grant any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly, or file (or participate in the filing of) a registration statement with the Securities and Exchange Commission (the “Commission”) in respect of, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission promulgated thereunder with respect to, any Common Stock or securities convertible into or exchangeable or exercisable for Common Stock, or warrants or other rights to purchase Common Stock or any such securities, (ii) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, or warrants or other rights to purchase Common Stock or any such securities, whether any such transaction is to be settled by delivery of Common Stock or such other securities, in cash or otherwise, or (iii) publicly announce an intention to effect any transaction specified in clause (i) or (ii) above. The foregoing sentence shall not apply to (a) the registration of the offer and sale of Common Stock as contemplated by the Underwriting Agreement and the sale of the Common Stock to the Underwriters (as defined in the Underwriting Agreement) in the Offering, (b) bona fide gifts, provided that the recipient thereof agrees in writing with the Managing Underwriters to be bound by the terms of this Lock-Up Agreement, (c) transfers to any trust, partnership or limited liability

company for the direct or indirect benefit of the undersigned and/or the immediate family of the undersigned, provided that such transferee agrees in writing with the Managing Underwriters to be bound by the terms of this Lock-Up Agreement, (d) if the undersigned is a corporation, limited liability company or partnership, transfers to a wholly-owned subsidiary of the undersigned or to the direct or indirect stockholders, members or partners or other affiliates of the undersigned, provided that no filing pursuant to Section 16 of the Securities Exchange Act of 1934, as amended, is required as result of such transfer and such transferee agrees in writing with the Managing Underwriters to be bound by the terms of this Lock-Up Agreement and (e) transfers which occur by operation of law, such as the rules of intestate succession, provided that such transferee agrees in writing with the Managing Underwriters to be bound by the terms of this Lock-Up Agreement. For purposes of this paragraph, “immediate family” shall mean the undersigned and the spouse, any lineal descendent, father, mother, brother, sister, father-in-law, mother-in-law, brother-in-law or sister-in-law of the undersigned.

          In addition, the undersigned hereby waives any rights the undersigned may have to require registration of Common Stock in connection with the filing of a registration statement relating to the Offering. The undersigned further agrees that, for the Lock-Up Period, the undersigned will not, without the prior written consent of the Managing Underwriters, make any demand for, or exercise any right with respect to, the registration of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, or warrants or other rights to purchase Common Stock or any such securities.

          Notwithstanding the above, if (a) during the period that begins on the date that is fifteen (15) calendar days plus three (3) business days before the last day of the Lock-Up Period and ends on the last day of the Lock-Up Period, the Company issues an earnings release or material news or a material event relating to the Company occurs; or (b) prior to the expiration of the Lock-Up Period, the Company announces that it will release earnings results during the sixteen (16) day period beginning on the last day of the Lock-Up Period, then the restrictions imposed by this Lock-Up Agreement shall continue to apply until the expiration of the date that is fifteen (15) calendar days plus three (3) business days after the date on which the issuance of the earnings release or the material news or material event occurs.

          In addition, the undersigned hereby waives any and all preemptive rights, participation rights, resale rights, rights of first refusal and similar rights that the undersigned may have in connection with the Offering or with any issuance or sale by the Company of any equity or other securities before the Offering, except for any such rights as have been heretofore duly exercised.

          The undersigned hereby confirms that the undersigned has not, directly or indirectly, taken, and hereby covenants that the undersigned will not, directly or indirectly, take, any action designed, or which has constituted or will constitute or might reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of shares of Common Stock.

* * *

          If (i) the Company notifies you in writing that it does not intend to proceed with the Offering, (ii) the registration statement filed with the Commission with respect to the Offering is withdrawn or (iii) for any reason the Underwriting Agreement shall be terminated prior to the “time of purchase” (as defined in the Underwriting Agreement), this Lock-Up Agreement shall be terminated and the undersigned shall be released from its obligations hereunder.

EXHIBIT B

FORM OF OPINION OF SPECIAL COMPANY COUNSEL

1.		The execution and delivery by the Company of the Underwriting Agreement and the consummation by the Company of the transactions contemplated thereby will not (A) constitute a violation of, or a breach or default under, the terms of any agreement or instrument of the Company set forth as an exhibit to the Registration Statement or (B) violate or conflict with, or result in any contravention of, any Applicable Law or any Applicable Order (it being understood that, for purposes of our opinion, (1) the term “Applicable Laws” means those laws, rules and regulations of the State of New York and the United States of America, in each case that, in our experience, are normally applicable to transactions of the type contemplated by the Underwriting Agreement (other than the United States federal securities laws, state securities or blue sky laws, antifraud laws and the rules and regulations of the National Association of Securities Dealers, Inc.), but without our having made any special investigation as to the applicability of any specific law, rule or regulation, all as of the date of such opinion, (2) the term “Applicable Orders” means those judgments, orders or decrees of Governmental Authorities (as such term is hereinafter defined) by which the Company is bound, the existence of which has been specifically disclosed to us in writing by the Company; and (3) the term “Governmental Authorities” means any court, regulatory body, administrative agency or governmental body of the State of New York or the United States of America having jurisdiction over the Company under Applicable Laws);
2.		No Governmental Approval, which has not been obtained or taken and is not in full force and effect, is required to authorize, or is required for, the execution or delivery of the Underwriting Agreement by the Company or the consummation by the Company of the transactions contemplated thereby (it being understood that, for purposes of our opinion, the term “Governmental Approval” means any consent, approval, license, authorization or validation of, or filing, qualification or registration with, any Governmental Authority required to be made or obtained by the Company pursuant to Applicable Laws, other than any consent, approval, license, authorization, validation, filing, qualification or registration that may have become applicable as a result of the involvement of any party (other than the Company) in the transactions contemplated by the Underwriting Agreement or because of such parties’ legal or regulatory status or because of any other facts specifically pertaining to such parties);
3.		Under current United States federal income tax law, although the discussion in the Prospectus under the caption “Material U.S. Federal Income Tax Consequences to Non-U.S. Holders” does not purport to summarize all possible United States federal income tax consequences of the purchase, ownership or disposition of the Shares, such discussion constitutes, in all material respects, a fair and accurate summary of the United States federal income tax consequences that are anticipated to be material to Non-U.S. Holders (as defined in the Prospectus) who purchase the Shares in the offering pursuant to the Prospectus; and

4.

The Company is not, and solely after giving effect to the offering and sale of the Shares and the application of the proceeds thereof as described in the Prospectus will not be, an “investment company” as such term is defined in the Investment Company Act of 1940, as amended.

In addition, we have participated in conferences with officers and other representatives of the Company, Davenport, Evans, Hurwitz & Smith, L.L.P., special South Dakota counsel for the Company, representatives of the independent accountants of the Company and you and Sidley Austin LLP, your counsel, at which the contents of the Registration Statement and the Prospectus, the General Disclosure Package (as defined below) and related matters were discussed. We do not pass upon, or assume any responsibility for, the accuracy, completeness or fairness of the statements contained in the Registration Statement or the Prospectus or the General Disclosure Package and have made no independent check or verification thereof (except to the limited extent referred to in paragraph 3 of our opinion to you dated the date hereof).

On the basis of the foregoing, (i) the Registration Statement, at the time it became effective, and the Prospectus, as of its date, appeared on their face to be appropriately responsive, in all material respects, to the requirements of the Securities Act and the General Rules and Regulations under the Securities Act (except that in each case we do not express any view as to the financial statements, schedules and other financial or statistical information included therein or excluded therefrom) and (ii) no facts have come to our attention that have caused us to believe that the Registration Statement, at the time it became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading or that the Prospectus, as of its date and as of the date hereof, contained or contains an untrue statement of a material fact or omitted or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading (except that in each case we do not express any view as to the financial statements, schedules and other financial or statistical information included therein or excluded therefrom or the statements contained in the exhibits to the Registration Statement). In addition, on the basis of the foregoing, no facts have come to our attention that have caused us to believe that the General Disclosure Package, as of the Applicable Time, contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading (except that we do not express any view as to the financial statements, schedules and other financial or statistical information included or incorporated by reference therein or excluded therefrom or the statements contained in the exhibits to the Registration Statement).

As used herein, “Applicable Time” means ___:00 [a./p.]m (Eastern time) on [insert date] and “General Disclosure Package” means the Preliminary Prospectus and the statements and other information in the Prospectus with respect to the public offering price and number of Shares, all considered together.

Such letter shall also state that we have reviewed the Notice of Effectiveness of the Securities and Exchange Commission posted on its website declaring the Registration Statement effective on [date].

EXHIBIT C

FORM OF OPINION OF COMPANY GENERAL COUNSEL

1.		Each of the Subsidiaries is validly existing as a corporation or other entity in good standing under the laws of its jurisdiction of incorporation, with full corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Registration Statement, the Preliminary Prospectus, the Prospectus, except where the failure to be in good standing would not, individually or in the aggregate, have a Material Adverse Effect.
2.		The Company and the Subsidiaries are each duly qualified to do business as a foreign corporation and are in good standing in each jurisdiction where the ownership or leasing of their respective properties or the conduct of their respective businesses requires such qualification, except where the failure to be so qualified and in good standing would not, individually or in the aggregate, have a Material Adverse Effect.
3.		The Company has an outstanding capitalization as set forth in the Prospectus. The 56,234,433 shares of Common Stock shown by the Company’s stock record books as being issued and outstanding immediately prior to the date hereof have been duly authorized and are validly issued and are fully paid and non-assessable (opinion to state that in rendering such opinion, I have relied solely on the stock record books of the Company in determining the number of all issued and outstanding shares of capital stock of the Company and have assumed that the consideration recited in the resolutions of the Board of Directors of the Company approving the issuance of all such shares has been received in full by the Company).
4.		All of the outstanding shares of capital stock of each of the Subsidiaries have been duly authorized and validly issued and are fully paid and non-assessable and, except as otherwise disclosed in the Registration Statement (excluding the exhibits thereto), the Preliminary Prospectus and the Prospectus, are owned by the Company, in each case subject to no security interest or, to my knowledge, other adverse claim.
5.		To my knowledge, (i) the Company is not party to any legal or governmental action or proceeding that challenges the validity or enforceability, or seeks to enjoin the performance, of the Underwriting Agreement; and (ii) there are no contracts or other documents that are required to be filed as exhibits to the Registration Statement pursuant to Item 601(b)(10) of Regulation S-K of the Rules and Regulations that are not so filed.
6.		To my knowledge, there are no legal or governmental proceedings pending or threatened to which the Company or any of its Subsidiaries is a party or to which any of the properties of the Company or any of its Subsidiaries is subject that are required to be disclosed in the Registration Statement or the Prospectus pursuant to Item 103 of Regulation S-K of the Rules and Regulations that are not so disclosed.

7.		Except as otherwise disclosed in the Registration Statement (excluding the exhibits thereto), the Preliminary Prospectus and the Prospectus, no person has the right, pursuant to any agreement or instrument of the Company set forth as an exhibit to the Registration Statement or otherwise known to me, to cause the Company to register under the Act any shares of Common Stock or shares of any other capital stock or other equity interest in the Company or to include any such shares or interest in the Registration Statement or the offering contemplated thereby.
8.		The execution, delivery and performance of the Underwriting Agreement by the Company, the issuance and sale of the Shares to be sold by the Company pursuant to the Underwriting Agreement and the consummation by the Company of the transactions contemplated by the Underwriting Agreement do not and will not result in any breach or violation of any decree, judgment or order applicable to the Company or any of the Subsidiaries or any of their respective properties, which decree, judgment or order is known by me.

In addition, I have participated in conferences with officers and other representatives of the Company, Davenport, Evans, Hurwitz & Smith, L.L.P., special South Dakota counsel for the Company, representatives of the independent accountants of the Company and you and Sidley Austin LLP, your counsel, at which the contents of the Registration Statement and the Prospectus, the General Disclosure Package (as defined below) and related matters were discussed. I do not pass upon, or assume any responsibility for, the accuracy, completeness or fairness of the statements contained in the Registration Statement or the Prospectus or the General Disclosure Package and have made no independent check or verification thereof.

On the basis of the foregoing, no facts have come to my attention that have caused me to believe that the Registration Statement, at the time it became effective, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading or that the Prospectus, as of its date and as of the date hereof, contained or contains an untrue statement of a material fact or omitted or omits to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading (except that in each case I do not express any view as to the financial statements, schedules and other financial or statistical information included therein or excluded therefrom or the statements contained in the exhibits to the Registration Statement). In addition, on the basis of the foregoing, no facts have come to my attention that have caused me to believe that the General Disclosure Package, as of the Applicable Time, contained an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading (except that I do not express any view as to the financial statements, schedules and other financial or statistical information included or incorporated by reference therein or excluded therefrom or the statements contained in the exhibits to the Registration Statement).

As used herein, “Applicable Time” means ___:00 [a./p.]m (Eastern time) on [insert date] and “General Disclosure Package” means the Preliminary Prospectus and the statements and other information in the Prospectus with respect to the public offering price and number of Shares, all considered together.

EXHIBIT D

OPINION OF SOUTH DAKOTA COMPANY COUNSEL

1.		The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of South Dakota, with full corporate power and authority to own, lease and operate its properties and conduct its business as described in the Registration Statement, the preliminary prospectus of the Company, dated November 29, 2006, relating to the Shares (the “Preliminary Prospectus”), the Prospectus and the Permitted Free Writing Prospectuses attached hereto as Annex A, to execute and deliver the Underwriting Agreement and to perform its obligations thereunder, including, without limitation, to issue, sell and deliver the Shares to be sold by the Company as contemplated by the Underwriting Agreement.
2.		The Underwriting Agreement has been duly authorized, executed and delivered by the Company.
3.		The Shares to be sold by the Company pursuant to the Underwriting Agreement have been duly authorized and validly issued and are fully paid and non-assessable.
4.		The Company has an authorized and, to our knowledge, outstanding capitalization as set forth in the Registration Statement, the Preliminary Prospectus and the Prospectus (and any similar sections or information, if any, contained in any Permitted Free Writing Prospectus attached hereto as Annex A); the Shares are free of statutory preemptive rights and, to our knowledge, contractual preemptive rights, resale rights, rights of first refusal and similar rights; the certificates for the Shares are in due and proper form; the Amended and Restated Articles of Incorporation of the Company and the Amended and Restated Bylaws of the Company, each in the form filed as an exhibit to the Registration Statement, have been heretofore duly authorized and adopted, have been filed with the South Dakota Secretary of State as required, and are in full force and effect as of the date hereof, in each case in accordance with the South Dakota Business Corporation Act.
5.		No approval, authorization, consent or order under the South Dakota Business Corporation Act or approval, authorization, consent of or filing with any South Dakota governmental or regulatory commission, board, body, authority or agency, or approval of the shareholders of the Company, is required in connection with the issuance and sale of the Shares to be sold by the Company pursuant to the Underwriting Agreement or with the consummation of the transactions contemplated by the Underwriting Agreement (except that we express no opinion as to any necessary qualification under the state securities or blue sky laws of the various jurisdictions in which the Shares are being offered by the Underwriters and we express no opinion with respect to the rules and regulations of the NASD).
6.		The execution, delivery and performance of the Underwriting Agreement by the Company, the issuance and sale of the Shares to be sold by the Company pursuant to the Underwriting Agreement and the consummation by the Company of the transactions

		contemplated by the Underwriting Agreement do not and will not result in any breach or violation of (i) the charter or bylaws of the Company or (ii) the South Dakota Business Corporation Act.
7.		The statements concerning the Company in the Registration Statement, the Preliminary Prospectus and the Prospectus under the heading “Description of Capital Stock,” insofar as such statements constitute summaries of the Company’s organizational documents or refer to matters of South Dakota law or legal conclusions relating thereto, are accurate and complete in all material respects and present fairly the information purported to be shown.

EXHIBIT E

OPINION OF UNDERWRITERS’ COUNSEL

     1. The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of South Dakota.

     2. The Common Stock being sold by the Company to the Underwriters pursuant to the Underwriting Agreement, when certificates therefor have been duly executed, countersigned and registered and delivered against payment of the agreed consideration therefor by the Underwriters in accordance with the terms of the Underwriting Agreement, will constitute shares of Common Stock which have been duly authorized and validly issued and are fully paid and non-assessable.

     3. The Underwriting Agreement has been duly authorized by all necessary corporate action of the Company and has been duly executed and delivered by the Company.

     4. The Common Stock conforms in all material respects to the description thereof contained in the Registration Statement.

     5. The Registration Statement has become effective under the Securities Act; and, to our knowledge, no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings for such purpose have been instituted or threatened by the SEC.

     6. At the time the Registration Statement became effective (but after giving effect to Rule 430A under the Securities Act), the Registration Statement (except for the financial statements, financial data, statistical data and supporting schedules included therein or in the exhibits thereto or omitted therefrom, as to which we express no opinion) complied as to form in all material respects with the requirements of the Securities Act.

     In the course of the preparation of the Registration Statement, the Preliminary Prospectus and the Prospectus we have considered the information set forth therein in light of the matters required to be set forth therein and, as noted above, we have participated in conferences with your representatives and officers and representatives of the Company, including its counsel and independent public accountants, during the course of which the contents of the Registration Statement, the Preliminary Prospectus and the Prospectus and related matters were discussed. We have not independently checked the accuracy or completeness of, or otherwise verified, and accordingly are not passing upon, and do not assume responsibility for, the accuracy, completeness or fairness of the statements contained in the Registration Statement, the Preliminary Prospectus or the Prospectus. However, as a result of such consideration and participation, no facts have come to our attention which have caused us to believe that:

     (A) the Registration Statement, at the time it became effective (but after giving effect to Rule 430A under the Securities Act), contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading; or

     (B) the Preliminary Prospectus, as of the Applicable Time and assuming with your permission that the Preliminary Prospectus had included as of the Applicable Time the information omitted from the Preliminary Prospectus as of the Applicable Time pursuant to Rule 430A under the Securities Act, included an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; or

     (C) the Prospectus, as of its date and as of the date hereof, included an untrue statement of a material fact or omitted to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

except in each case that we express no belief and make no statement with respect to financial statements, financial data, statistical data and supporting schedules included in or omitted from the Registration Statement, the Preliminary Prospectus as of Applicable Time or the Prospectus.

     To the extent that any matters covered by the foregoing opinions may involve the laws of the State of South Dakota, including, without limitation, the South Dakota Business Corporation Act, such counsel need not have made an independent investigation of such laws but may rely exclusively on the opinion of South Dakota counsel to the Company, subject to the exceptions, qualifications and limitations therein expressed.

EXHIBIT F

OFFICERS’ CERTIFICATE

          Each of the undersigned, Gordon Ommen, Chief Executive Officer of US BioEnergy Corporation, a South Dakota corporation (the “Company”), and Rich Atkinson, Chief Financial Officer of the Company, on behalf of the Company, does hereby certify pursuant to Section 6(k) of that certain Underwriting Agreement dated [pricing date] (the “Underwriting Agreement”) among the Company and, on behalf of the several Underwriters named therein, UBS Securities LLC and Piper Jaffray & Co., Inc., that as of [date]:

1.		He has reviewed the Registration Statement, each Preliminary Prospectus, the Prospectus and each Permitted Free Writing Prospectus.
2.		The representations and warranties of the Company as set forth in the Underwriting Agreement are true and correct as of the date hereof and as if made on the date hereof.
3.		The Company has performed all of its obligations under the Underwriting Agreement as are to be performed at or before the date hereof.
4.		The conditions set forth in paragraph (j) of Section 6 of the Underwriting Agreement have been met.

          Capitalized terms used herein without definition shall have the respective meanings ascribed to them in the Underwriting Agreement.

          In Witness Whereof, the undersigned have hereunto set their hands on this [date].