EMPLOYEE STOCK PURCHASEPLAN

Exhibit 10.2

ONEOK, INC.

EMPLOYEE STOCK PURCHASE PLAN

The purpose of this Plan is to provide eligible employees the opportunity to purchase Common Stock at a discount on a basis that qualifies for the tax treatment prescribed by Section 423 of the Code.

The following terms, when used in the Plan, shall have the following meanings:

(a) Base Compensation means, with respect to any offering period: (i) in the case of an employee normally paid an hourly rate, the employee’s hourly rate at the inception of the offering period multiplied by 2,080, (ii) in the case of an employee normally paid at a weekly rate, the employee’s weekly rate at the inception of the offering period multiplied by 52, (iii) in the case of an employee normally paid at a bi-weekly rate, the employee’s bi-weekly rate at the inception of the offering period multiplied by 26, (iv) in the case of an employee normally paid at a monthly rate, the employee’s monthly rate at the inception of the offering period multiplied by 12; and (v) in the case of an employee normally paid at an annual rate, the employee’s annual rate at the inception of the offering period. Base compensation shall be determined by reference to the applicable rate before any deductions pursuant to a salary reduction agreement under any plan qualified under Section 401(k) of the Code or any cafeteria plan under Code Section 125 and shall exclude any bonuses, commissions, overtime pay, fringe benefits, stock options and other special compensation payable to an employee.

(b) Board or Board of Directors means the Board of Directors of the Company, as constituted from time to time.

(c) Code means the Internal Revenue Code of 1986, as amended from time to time. References to the Code or to a particular section of the Code shall include references to any related Treasury Regulations and rulings and to successor provisions.

(d) Committee means the committee appointed by the Board of Directors to administer the Plan pursuant to the provisions of Section 3(a) below.

(e) Common Stock means common stock, par value $0.01, of the Company.

(f) Company means ONEOK, Inc., an Oklahoma corporation, its successors and assigns.

(g) Exchange Act means the Securities Exchange Act of 1934, as amended from time to time.

(h) Fair Market Value on a particular date means the average of the high and low sale prices of the Common Stock in consolidated trading on the date in question as reported by The Wall Street Journal or another reputable source designated by the Committee; provided that if there were no sales on such date reported as provided above, the respective prices on the most recent prior day for which a sale was so reported. If the foregoing method of determining fair market value should be inconsistent with Section 423 of the Code, “Fair Market Value” shall be determined by the Committee in a manner consistent with such section of the Code and shall mean the value as so determined.

(i) General Counsel means the General Counsel of the Company serving from time to time.

(j) Plan means the ONEOK, Inc. Employee Stock Purchase Plan set forth in these pages, as amended from time to time.

(k) SEC Rule 16b-3 means Rule 16b-3 of the Securities and Exchange Commission promulgated under the Exchange Act, as such rule or any successor rule may be in effect from time to time.

(l) Section 16 Person means a person subject to Section 16(b) of the Exchange Act with respect to transactions involving equity securities of the Company.

(m) Subsidiary means a subsidiary as defined in Section 424(f) of the Code, including a corporation which becomes such a subsidiary in the future.

(a) The Plan shall be administered by a committee of the Board consisting of two or more directors appointed from time to time by the Board. No person shall be appointed to or shall serve as a member of such committee unless at the time of such appointment and service he or she shall be a Non-Employee Director, as defined in SEC Rule 16b-3.

(b) Subject to the provisions of the Plan, the powers of the Committee shall include having the authority, in its discretion, to:

(i) define, prescribe, amend and rescind rules, regulations, procedures, terms and conditions relating to the Plan; and

(ii) make all other determinations necessary or advisable for the administration of the Plan, including but not limited to interpreting the Plan, correcting defects, reconciling inconsistencies and resolving ambiguities.

(iii) approve any transaction involving a grant, award or other transaction from the Company to a Section 16 Person (other than a Discretionary Transaction, as defined in SEC Rule 16b-3), so as to exempt such transaction under SEC Rule 16b-3; provided, that any transaction under the Plan involving a Section 16 Person also may be approved by the Board of Directors, or may be

approved or ratified by the stockholders of the Company, in the manner that exempts such transaction under SEC Rule 16b-3.

(c) The interpretation by the Committee of the terms and provisions of the Plan, and its administration of the Plan, and all action taken by the Committee, shall be final, binding and conclusive on the Company, its stockholders, Subsidiaries, all participants and employees, and upon their respective successors and assigns, and upon all other persons claiming under or through any of them.

(d) Members of the Board and members of the Committee acting under this Plan shall be fully protected in relying in good faith upon the advice of counsel and shall incur no liability except for gross or willful misconduct in the performance of their duties.

(a) Subject to paragraph (c) below, the aggregate number of shares of Common Stock which may be sold under the Plan is 3,800,000 .

(b) If the number of shares of Common Stock that participating employees become entitled to purchase is greater than the number of shares of Common Stock that are offered in a particular offering or that remain available under the Plan, the available shares of Common Stock shall be allocated by the Committee among such participating employees in such manner as it deems fair and equitable.

(c) In the event of any change in the Common Stock, through recapitalization, merger, consolidation, stock dividend or split, combination or exchange of shares, spinoff or otherwise, the Committee may make such equitable adjustments in the Plan and the then outstanding offerings as it deems necessary and appropriate including, but not limited to, changing the number of shares of Common Stock reserved under the Plan, and the price of the current offering; provided that any such adjustments shall be consistent with Sections 423 and 424 of the Code.

(d) Shares of Common Stock which are to be delivered under the Plan may be obtained by the Company from its treasury, by purchases on the open market or from private sources, or by issuing authorized but unissued shares of its Common Stock. Shares of authorized but unissued Common Stock may not be delivered under the Plan if the purchase price thereof is less than the par value (if any) of the Common Stock at the time. The Committee may (but need not) provide at any time or from time to time (including without limitation upon or in contemplation of a change in control) for a number of shares of Common Stock equal in number to the number of shares then subject to options under this Plan, or expected to be subject to options under this Plan in the then pending offering(s), to be issued or transferred to, or acquired by, a trust (including but not limited to a grantor trust) for the purpose of satisfying the Company’s obligations under such options, and, unless prohibited by applicable law, such shares held in trust shall be considered authorized and issued shares with full dividend and voting rights, notwithstanding that the options to which such shares relate might not be exercisable at the time. No fractional shares of Common Stock shall be issued or sold under the Plan.

All employees of the Company and any Subsidiaries designated by the Committee from time to time will be eligible to participate in the Plan, in accordance with and subject to such rules and regulations as the Committee may prescribe; provided, however, that (a) such rules shall neither permit nor deny participation in the Plan contrary to the requirements of the Code (including but not limited to Section 423(b)(3), (4) and (8) thereof), (b) no employee shall be eligible to participate in the Plan if his or her customary employment is 20 hours or less per week or for not more than 5 months in any calendar year, unless the Committee determines otherwise on a uniform and non-discriminatory basis, (c) no employee may be granted an option under the Plan if such employee, immediately after the option is granted, owns stock possessing 5% or more of the total combined voting power or value of all classes of stock of his or her employer corporation or any parent or Subsidiary corporation (within the meaning of Section 423(b)(3) of the Code). For purposes of the preceding sentence, the rules of Section 424(d) of the Code shall apply in determining the stock ownership of an employee, and stock which the employee may purchase under outstanding options (whether or not such options qualify for the special tax treatment afforded by Code Section 421(a)) shall be treated as stock owned by the employee; and (d) all participating employees shall have the same rights and privileges except as otherwise permitted by Section 423(b)(5) of the Code.

The Company may make offerings of up to 27 months’ duration each, to eligible employees to purchase Common Stock under the Plan, until all shares authorized to be delivered under the Plan have been exhausted or until the Plan is sooner terminated by the Board. Subject to the preceding sentence, the duration and commencement date of any offerings shall be determined by the Committee in its sole discretion; provided that, unless the Committee determines otherwise, a new offering shall commence on the first day of the Company’s first payroll period coinciding with or next following each January 1 after the effective date of this Plan and shall extend through and include the payroll period immediately preceding the payroll period in which the next offering commences. Subject to such rules, procedures and forms as the Committee may prescribe, an eligible employee may participate in an offering at such time(s) as the Committee may permit by authorizing a payroll deduction for such purpose of up to a maximum of ten percent of his or her Base Compensation or such lesser amount as the Committee may prescribe. The Committee may (but need not) permit employee contributions to be made by means other than payroll deductions, provided that in no event shall an employee’s contributions from all sources in any offering exceed ten percent of his or her Base Compensation or such lesser amount as the Committee may prescribe. The Committee may at any time suspend or accelerate the completion of an offering if required by law or deemed by the Committee to be in the best interests of the Company, including in the event of a change in ownership or control of the Company or any Subsidiary. The Company’s obligation to sell and deliver Common Stock under this Plan shall be subject to the approval of any governmental authority whose approval the General Counsel determines is necessary or advisable to obtain in connection with the authorization, issuance or sale of such Common Stock.

(a) The Company will maintain payroll deduction accounts on its books for all participating employees. All employee contributions shall be credited to such accounts. Employee contributions credited to the payroll deduction accounts of participating employees need not be segregated from other corporate funds and may be used for any corporate purpose.

(b) At such times as the Committee may permit and subject to such rules, procedures and forms as the Committee may prescribe, an employee may increase, decrease or suspend his or her payroll deduction during an offering, or may withdraw the balance of his or her payroll deduction account and thereby withdraw from participation in an offering. However, an employee may at any time waive in writing the right or privilege to decrease or suspend his or her payroll deductions or withdraw from participation in a particular offering for a period of at least six months. Any such waiver shall be irrevocable with respect to the period ending six months after the employee files a superseding written revocation of such waiver with the Company.

(c) No employee shall make any elective contribution or employee contribution to the Plan (within the meaning of Treasury Regulation Section 1.401(k)-1(d)(2)(iv)(B)(4)) during the balance of the calendar year after the employee’s receipt of a hardship distribution from a plan of the Company or a related party within the provisions of Code Section 414(b), (c), (m) or (o) containing a cash or deferred arrangement under Section 401(k) of the Code, or during the following calendar year. The foregoing sentence shall not apply if and to the extent the General Counsel determines it is not necessary to qualify any such plan as a cash or deferred arrangement under Section 401(k) of the Code.

(d) Any balance remaining in any employee’s payroll deduction account at the end of an offering period will be carried forward into the employee’s payroll deduction account for the following offering period. In no event will the balance carried forward be equal to or greater than the purchase price of one share of Common Stock as determined under Section 8(c) below. Any excess shall be refunded to the participant. Upon termination of the Plan, all amounts in the accounts of participating employees shall be carried forward into their payroll deduction accounts under a successor plan, if any, or refunded to them, as the Committee may decide.

(e) In the event of the termination of a participating employee’s employment for any reason, his or her participation in any offering under the Plan shall cease, no further amounts shall be deducted pursuant to the Plan and the balance in the employee’s account shall be paid to the employee, or, in the event of the employee’s death, to the employee’s beneficiary under the Company’s basic group life insurance program.

(a) Within the limitations of Section 8(d) below, each employee participating in any offering under the Plan will be granted an option, upon the effective date of such offering, for as many full shares of Common Stock as the amount of his or her payroll deduction account (including

any contributions made by means other than payroll deductions) at the end of the offering can purchase.

(b) As of the last day of the offering period, the payroll deduction account of each participating employee shall be totaled. Subject to the provisions of Section 7(b) above and 8(d) below, if such account contains sufficient funds as of that date to purchase one or more full shares of Common Stock at the price determined under Section 8(c) below, the employee shall be deemed to have exercised an option to purchase the largest number of full shares of Common Stock at the price determined under Section 8(c) below that his or her payroll deduction account will permit; such employee’s account will be charged for the amount of the purchase and for all purposes under the Plan the employee will be deemed to have acquired the shares on that date; and either a stock certificate representing such shares will be issued to him or her, or the Company’s registrar will make an entry on its books and records evidencing that such shares have been duly issued or transferred as of that date, as the Committee may direct. Notwithstanding any provision of the Plan to the contrary, the Committee may but need not permit fractional shares to be purchased under the Plan.

(c) Unless the Committee determines before the effective date of an offering that a higher price that complies with Section 423 of the Code shall apply, the purchase price of the shares of Common Stock which are to be sold under the offering shall be the lesser of (i) an amount equal to 85 percent of the Fair Market Value of the Common Stock at the time such option is granted, or (ii) an amount equal to 85 percent of the Fair Market Value of the Common Stock at the time such option is exercised.

(d) In addition to any other limitations set forth in the Plan, (i) no employee may purchase in any offering period more than the number of shares of Common Stock determined by dividing the employee’s annual Base Compensation as of the first day of the offering period, or $25,000, whichever is less, by the Fair Market Value of a share of Common Stock at such day, and (ii) no employee may be granted an option under the Plan which permits his or her rights to purchase stock under the Plan, and any other stock purchase plan of his or her employer corporation and its parent and subsidiary corporations that is qualified under Section 423 of the Code, to accrue at a rate which exceeds $25,000 of the Fair Market Value of such stock (determined at the time such option is granted) for each calendar year in which the option is outstanding at any time. The Committee may further limit the amount of Common Stock which may be purchased by any employee during an offering period in accordance with Section 423(b)(5) of the Code.

(a) No option, right or benefit under the Plan (including any derivative security within the meaning of paragraph (a)(2) of SEC Rule 16b-3) may be transferred by a participating employee, whether by will, the laws of descent and distribution, or otherwise, and all options, rights and benefits under the Plan may be exercised during the participating employee’s lifetime only by such employee.

(b) Book entry accounts and certificates for shares of Common Stock purchased under the Plan may be maintained or registered, as the case may be, only in the name of the participating

employee or, if such employee so indicates on his or her payroll deduction authorization form, in his or her name jointly with a member of his or her family, with right of survivorship. An employee who is a resident of a jurisdiction which does not recognize such a joint tenancy may have book entry accounts maintained and certificates registered in the employee’s name as tenant in common with a member of the employee’s family, without right of survivorship.

The Plan shall become effective when adopted by the Board, provided that the stockholders of the Company approve it within 12 months thereafter at a duly held stockholders’ meeting. If not so approved by shareholders, the Plan shall be null, void and of no force or effect. If so approved, the Plan shall remain in effect until all shares authorized to be issued or transferred hereunder have been exhausted or until the Plan is sooner terminated by the Board of Directors, and may continue in effect thereafter with respect to any options outstanding at the time of such termination if the Board of Directors so provides.

The Plan may be amended by the Board of Directors, without shareholder approval, at any time and in any respect, unless shareholder approval of the amendment in question is required under Oklahoma law, the Code (including without limitation Code Section 423 and Treasury Regulation Section 1.423-2(c)(4) thereunder), any exemption from Section 16 of the Exchange Act (including without limitation SEC Rule 16b-3) for which the Company intends Section 16 Persons to qualify, any national securities exchange or system on which the Stock is then listed or reported, by any regulatory body having jurisdiction with respect to the Plan, or under any other applicable laws, rules or regulations. The Plan provisions that determine the amount, price and timing of option grants to Section 16 Persons may not be amended more than once every six months, other than to comport with changes in the Internal Revenue Code, the Employee Retirement Income Security Act of 1974, or the rules thereunder, unless the General Counsel determines that such restriction on amendments is not necessary to secure or maintain any exemption from Section 16 of the Exchange Act for which the Company intends Section 16 Persons to qualify. The Plan may also be terminated at any time by the Board of Directors.

(a) Nothing contained in this Plan shall be deemed to confer upon any person any right to continue as an employee of or to be associated in any other way with the Company for any period of time or at any particular rate of compensation.

(b) No person shall have any rights as a stockholder of the Company with respect to any shares optioned under the Plan until such shares are issued or transferred to him or her.

(c) All expenses of adopting and administering the Plan shall be borne by the Company, and none of such expenses shall be charged to any participant.

(d) The Plan shall be governed by and construed under the laws of the State of Oklahoma, without giving effect to the principles of conflicts of laws of that State.

(e) The Plan and each offering under the Plan is intended to qualify as an employee stock purchase plan within the meaning of Section 423 of the Code. Transactions under the Plan by or with respect to Section 16 Persons are also intended to qualify for exemption under SEC Rule 16b-3, unless the Committee specifically determines otherwise. Every provision of the Plan shall be administered, interpreted and construed to carry out those intentions, and any provision that cannot be so administered, interpreted and construed shall to that extent be disregarded.