AMENDMENT NO. 4 AND WAIVER TO THE AMENDED AND RESTATED SALE AND SERVICING AGREEMENT

Exhibit 10.7.6

AMENDMENT NO. 4 AND WAIVER TO THE AMENDED AND

RESTATED SALE AND SERVICING AGREEMENT

THIS AMENDMENT NO. 4 AND WAIVER TO THE AMENDED AND RESTATED SALE AND SERVICING AGREEMENT, dated as of October 30, 2006 (this “Amendment”), is entered into in connection with that certain Amended and Restated Sale and Servicing Agreement, dated as of April 5, 2006 (such agreement as amended, modified, supplemented, waived or restated from time to time, the “Agreement”), by and among NEWSTAR CP FUNDING LLC, a Delaware limited liability company, as the seller (together with its successors and assigns in such capacity, the “Seller”), NEWSTAR FINANCIAL INC., a Delaware corporation (together with its successors and assigns, the “Company”), as the originator (together with its successors and assigns in such capacity, the “Originator”), and as the servicer (together with its successors and assigns in such capacity, the “Servicer”), WACHOVIA BANK, NATIONAL ASSOCIATION, a national banking association (together with its successors and assigns, “Wachovia”), as the swingline purchaser (together with its successors and assigns in such capacity, the “Swingline Purchaser”), certain conduit purchasers and purchaser agents party thereto (each, together with its successors and assigns in such capacity, a “Conduit Purchaser” and a “Purchaser” and, collectively with the Swingline Purchaser, the “Purchasers”), WACHOVIA CAPITAL MARKETS, LLC, a Delaware limited liability company (together with its successors and assigns, “WCM”), as the administrative agent (together with its successors and assigns in such capacity, the “Administrative Agent”), and as the Purchaser Agent with respect to Variable Funding Capital Company LLC as Conduit Purchaser (together with its successors and assigns in such capacity, the “VFCC Agent”), U.S. BANK NATIONAL ASSOCIATION, a national banking association (together with its successors and assigns, “US Bank”), not in its individual capacity but as the trustee (together with its successors and assigns in such capacity, the “Trustee”), and LYON FINANCIAL SERVICES, INC., a Minnesota corporation, doing business as U.S. Bank Portfolio Services, not in its individual capacity but as the backup servicer (together with its successors and assigns in such capacity, the “Backup Servicer”). Capitalized terms used and not otherwise defined herein are used as defined in the Agreement.

R E C I T A L S

WHEREAS, the parties hereto previously entered into the Agreement;

WHEREAS, the parties hereto desire to amend the Agreement in certain respects as provided herein; and

WHEREAS, pursuant to and in accordance with Section 13.1 thereof, the Administrative Agent and VFCC Agent, the Swingline Purchaser and the Conduit Purchasers desire to provide for a one-time waiver of certain provisions of the Agreement in certain respects as provided herein;

NOW, THEREFORE, based upon the above Recitals, the mutual premises and agreements contained herein, and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto, intending to be legally bound, hereby agree as follows:

SECTION 1. Amendments.

(a) Section 2.19(a)(viii) of the Agreement is hereby amended by inserting the following parenthetical after the words “Discretionary Sales”:

“(other than the Discretionary Sales of Assets (i) occurring within 90 days after any such Asset became part of the Collateral and (ii) where following any such Discretionary Sale, a portion of such Asset remained part of the Collateral)”.

(b) Section 2.21(a)(iii) of the Agreement is hereby amended by inserting the following parenthetical after the words “Discretionary Sale”:

“(other than the Discretionary Sales of Assets (i) occurring within 90 days after any such Asset becomes part of the Collateral and (ii) where following any such Discretionary Sale, a portion of such Asset remains part of the Collateral)”.

(c) Section 2.21(a)(iv) of the Agreement is hereby amended by inserting the following parenthetical after the words “preceding 12 month period” in the first sentence thereof:

“(which amount shall not include the aggregate Principal Balance of any Asset sold in a Discretionary Sale made in the preceding 12 month period where (i) the Discretionary Sale occurred within 90 days after such Asset became part of the Collateral and (ii) following such Discretionary Sale, a portion of such Asset remained part of the Collateral)”.

SECTION 2. Waiver.

Each of the Administrative Agent and VFCC Agent, the Swingline Purchaser and the Conduit Purchaser hereby waives:

(a) the failure of the sum of the Principal Balances of Eligible Assets which are included in the “Buildings and Real Estate” Moody’s Industrial Classification Group to satisfy the limit set forth in clause (r) of the definition of “Concentration Limit” and hereby agrees that such Assets shall be deemed not to exceed such Concentration Limit for all purposes of the Agreement and the other Transaction Documents; provided that the waiver described in this clause (a) shall be effective from and as of the date hereof until January 29, 2007; and

(b) the occurrence of a fact such that Assets identified on Schedule I hereto would be otherwise deemed to be a Delinquent Loan by reason that all or any portion of any one or more payments of principal or interest thereunder remains unpaid for at least 60 days from the original

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due date for such payment (without giving effect to any Servicer Advance thereon or any grace period permitted in the Underlying Instrument) and hereby agrees such Assets shall be deemed not to be Delinquent Loans for all purposes of the Sale and Servicing Agreement and the other Transaction Documents; provided that the waiver described in this clause (b) shall be effective from and as of the date hereof until November 29, 2006.

For the avoidance of doubt, the waivers described in this Section 2 shall expire in accordance with its terms and shall be of no further force and effect as of the respective dates specified in the foregoing clauses.

SECTION 3. Agreement in Full Force and Effect as Amended and Waived.

Except as specifically amended and waived hereby, the Agreement shall remain in full force and effect. All references to the Agreement shall be deemed to mean the Agreement as modified hereby. This Amendment shall not constitute a novation of the Agreement, but shall constitute an amendment thereof. The parties hereto agree to be bound by the terms and conditions of the Agreement, as amended and waived by this Amendment, as though such terms and conditions were set forth herein.

SECTION 4. Representations and Warranties.

Each of the Originator, the Seller and the Servicer represents and warrants with respect to itself as of the date of this Amendment as follows:

(a) it is duly incorporated or organized, validly existing and in good standing under the laws of its jurisdiction of incorporation or organization;

(b) the execution, delivery and performance by it of this Amendment are within its powers, have been duly authorized, and do not contravene (A) its charter, by-laws, or other organizational documents, or (B) any Applicable Law;

(c) no consent, license, permit, approval or authorization of, or registration, filing or declaration with any governmental authority, is required in connection with the execution, delivery, performance, validity or enforceability of this Amendment by or against it;

(d) this Amendment has been duly executed and delivered by it;

(e) this Amendment constitutes its legal, valid and binding obligation enforceable against it in accordance with its terms, except as enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the enforcement of creditors’ rights generally or by general principles of equity;

(f) it is not in default under the Agreement; and

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(g) there is no Termination Event, Unmatured Termination Event, or Servicer Default.

SECTION 5. Conditions Precedent.

This Amendment shall become effective on the date on which each party hereto has delivered an executed signature page hereto to the Administrative Agent.

SECTION 6. Miscellaneous.

(a) This Amendment may be executed in any number of counterparts, and by the different parties hereto on the same or separate counterparts, each of which shall be deemed to be an original instrument but all of which together shall constitute one and the same agreement.

(b) The descriptive headings of the various sections of this Amendment are inserted for convenience of reference only and shall not be deemed to affect the meaning or construction of any of the provisions hereof.

(c) This Amendment may not be amended or otherwise modified except as provided in the Agreement.

(d) The failure or unenforceability of any provision hereof shall not affect the other provisions of this Amendment.

(e) Whenever the context and construction so require, all words used in the singular number herein shall be deemed to have been used in the plural, and vice versa, and the masculine gender shall include the feminine and neuter and the neuter shall include the masculine and feminine.

(f) This Amendment represents the final agreement between the parties and may not be contradicted by evidence of prior, contemporaneous or subsequent oral agreements between the parties. There are no unwritten oral agreements between the parties.

(g) THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES UNDER THIS AMENDMENT SHALL BE GOVERNED BY AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK WITHOUT REFERENCE TO ITS CONFLICT OF LAWS PROVISIONS.

[Remainder of Page Intentionally Left Blank]

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IN WITNESS WHEREOF, the parties have caused this Amendment to be executed by their respective officers thereunto duly authorized, as of the date first above written.

[Signatures Continued on the Following Page]

Amendment No. 4 to Amended and Restated

Sale and Servicing Agreement

Amendment No. 4 to Amended and Restated

Sale and Servicing Agreement

Schedule I to

Amendment No. 4 and

Waiver dated

October 30, 2006

List of Assets