LOAN SALE AGREEMENT

Exhibit 99.3

LOAN SALE AGREEMENT

between

HERCULES FUNDING I LLC

as Depositor

and

HERCULES TECHNOLOGY GROWTH CAPITAL, INC.

as Originator

Dated as of August 1, 2005

HERCULES FUNDING TRUST I

ASSET BACKED NOTES

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LOAN SALE AGREEMENT

LOAN SALE AGREEMENT, dated as of August 1, 2005 (this “ Agreement ”), between HERCULES TECHNOLOGY GROWTH CAPITAL, INC., a Maryland corporation (the “ Originator ”), and HERCULES FUNDING I LLC, a Delaware limited liability company (the “ Depositor ”).

W I T N E S S E T H

WHEREAS, the Originator owns and from time to time originates certain commercial loans secured by, among other things, accounts receivable, inventory, real estate, and/or other tangible or intangible property;

WHEREAS, the Originator is the owner of 100% of the membership interests of the Depositor;

WHEREAS, the parties hereto desire that on each Transfer Date the Originator sell all its right, title and interest in and to the Assigned Assets identified in the related LSA Assignment to the Depositor pursuant to the terms of this Agreement; and

WHEREAS, on the Closing Date, to the extent of any Assigned Assets sold hereunder on the Closing Date, and on each Transfer Date, with respect to the Assigned Assets identified in the applicable LSA Assignment the Depositor will sell and assign all of its right, title and interest in and to the Assigned Assets and its related rights under this Agreement to Hercules Funding Trust I, as Issuer (the “ Issuer ”), and on the Closing Date the Depositor will further assign its related rights under this Agreement to the Issuer, all pursuant to the terms of the Sale and Servicing Agreement, dated as of August 1, 2005 (the “ Sale and Servicing Agreement ”), among the Issuer, the Depositor, the Originator, the Servicer, U.S. Bank National Association, as Collateral Custodian (in such capacity, the “ Collateral Custodian ”), as Indenture Trustee (in such capacity, the “ Indenture Trustee ”) on behalf of the related Noteholders and Lyon Financial Services, Inc. doing business as U.S. Bank Portfolio Services, as Backup Servicer (in such capacity, the “ Backup Servicer ”);

NOW, THEREFORE, in consideration of the mutual covenants herein contained, the parties hereto agree as follows:

ARTICLE I

DEFINITIONS; CONSTRUCTION

Section 1.01 Definitions . Whenever used in this Agreement, the following words and phrases, unless the context otherwise requires, shall have the meanings specified in this Article. All other capitalized terms used but not defined herein shall have the meanings assigned thereto in the Sale and Servicing Agreement.

“ Assigned Assets ”: All right, title and interest, whether now owned or hereafter acquired or arising, and wherever located, of the Originator in and to the property described in clauses (i) through (x) below and all accounts, cash and currency, chattel paper, tangible chattel

paper, electronic chattel paper, copyrights, copyright licenses, equipment, fixtures, contract rights, general intangibles, instruments, certificates of deposit, certificated securities, uncertificated securities, financial assets, securities entitlements, commercial tort claims, deposit accounts, inventory, investment property, letter-of-credit rights, software, supporting obligations, accessions, and other property consisting of, arising out of, or related to any of the following (in each case excluding the Retained Interest and the Excluded Amounts):

(i) the Transferred Loans, and all monies due or to become due in payment of such Transferred Loans on and after the related Transfer Date, including but not limited to all Collections and all obligations owed to the Originator in connection with the Transferred Loans;

(ii) any Related Property securing or purporting to secure the Transferred Loans (to the extent the Originator, other than solely in its capacity as collateral agent under any loan agreement with an Obligor, has been granted a Lien thereon) including the related security interest granted by the Obligor under the Transferred Loans, all proceeds from any sale or other disposition of such Related Property;

(iii) all security interests, liens, guaranties, warranties, letters of credit, accounts, bank accounts, mortgages or other encumbrances and property subject thereto from time to time purporting to secure payment of any Transferred Loan, together with all UCC financing statements or similar filings relating thereto;

(iv) all claims (including “claims” as defined in Bankruptcy Code § 101(5)), suits, causes of action, and any other right of the Originator, whether known or unknown, against the related Obligors, if any, or any of their respective Affiliates, agents, representatives, contractors, advisors, or any other Person that in any way is based upon, arises out of or is related to any of the foregoing, including, to the extent permitted to be assigned under applicable law, all claims (including contract claims, tort claims, malpractice claims, and claims under any law governing the purchase and sale of, or indentures for, securities), suits, causes of action, and any other right of the Originator against any attorney, accountant, financial advisor, or other Person arising under or in connection with the related Loan Documents;

(v) all cash, securities, or other property, and all setoffs and recoupments, received or effected by or for the account of the Originator under such Transferred Loans (whether for principal, interest, fees, reimbursement obligations, or otherwise) after the related Transfer Date, including all distributions obtained by or through redemption, consummation of a plan of reorganization, restructuring, liquidation, or otherwise of any related Obligor or the related Loan Documents, and all cash, securities, interest, dividends, and other property that may be exchanged for, or distributed or collected with respect to, any of the foregoing;

(vi) all Insurance Policies;

(vii) the Loan Documents with respect to such Transferred Loans;

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(viii) the Collection Account, the Principal Collections Account, the Distribution Account, and the Concentration Account (to the extent that amounts on deposit in or credited to the Concentration Account relate to the Collateral), together with all funds held in or credited to such accounts (to the extent that amounts on deposit in or credited to the Concentration Account relate to the Collateral), and all certificates and instruments, if any, from time to time representing or evidencing each of the foregoing or such funds;

(ix) any Hedging Agreement and any payment from time to time due thereunder; and

(x) the proceeds of each of the foregoing.

“ Purchase Price ”: Has the meaning provided in Section 2.01(b) .

Section 1.02 Construction . For purposes of this Agreement: (i) the singular includes the plural and the plural includes the singular; (ii) words importing any gender include the other genders; (iii) the words “and” and “or” are used in the conjunctive or disjunctive as the sense and circumstances may require, (iv) references to “writing” include printing, typing, lithography and other means of reproducing words in a visible form; (v) references to agreements and other contractual instruments include all subsequent amendments thereto or changes therein entered into in accordance with their respective terms and not prohibited by this Agreement or the Basic Documents; (vi) references to Persons include their permitted successors and assigns; (vii) any form of the word “include” shall be deemed to be followed by the words “without limitation”; (viii) the phrase “in and to” shall be deemed to include “under” and “with respect to” whenever appropriate; (ix) unless the context clearly requires otherwise, the word “finance” shall be deemed to include “refinance”; (x) the words “herein”, “hereof’ and “hereunder” and other words of similar import refer to this Agreement as a whole and not to any particular Article, Section or other subdivision; and (xi) Article, Section, Schedule and Exhibit references, unless otherwise specified, refer to Articles and Sections of and Schedules and Exhibits to this Agreement. Unless otherwise stated in this Agreement, in the computation of a period of time from a specified date to a later specified date, the word “from” means “from and including” and the words “to” and “until” each mean “to but excluding.”

ARTICLE II

SALE OF THE ASSIGNED ASSETS; PAYMENT OF PURCHASE PRICE

Section 2.01 Sale of the Assigned Assets to the Depositor . (a) On the terms and conditions of this Agreement, on each Transfer Date during the Revolving Period, the Originator agrees to offer for sale and to sell, the Assigned Assets described in the related LSA Assignment substantially in the form attached hereto as Exhibit A (the “ LSA Assignment ”) to the Depositor and to deliver the related Loan Documents to or at the direction of the Depositor and the Depositor agrees to purchase such Assigned Assets offered for sale by the Originator.

(b) The purchase price for each Transferred Loan and the Related Property and other collateral constituting part of the Assigned Assets with respect to such Transferred

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(c) On each Transfer Date, the Originator shall convey to the Depositor the Assigned Assets and the other property and rights related thereto described in the related LSA Assignment to be delivered by the Originator, and, upon the satisfaction of each of the conditions set forth in this Section 2.01(c) and in Section 2.08 of the Sale and Servicing Agreement on or prior to such Transfer Date, the Depositor shall pay or cause to be paid to or at the direction of the Originator, the aggregate Purchase Price in respect of the Assigned Assets sold hereunder on such Transfer Date.

(i) the Originator shall have provided to the Servicer for deposit in the related Collection Account all collections received with respect to each Transferred Loan constituting a part of the Assigned Assets relating to the period after the applicable Transfer Date;

(ii) the Originator shall, at its own expense, within one Business Day after each Transfer Date, indicate in its computer files that the Assigned Assets identified in the related LSA Assignment have been sold to the Depositor pursuant to this Agreement;

(iii) the Originator shall have taken any action requested by the Indenture Trustee, the Issuer or the Noteholders required to maintain the ownership interest of the Issuer in the Assigned Assets and the first perfected security interest therein of the Indenture Trustee;

(iv) the Originator shall have used no selection procedures that identified any of the Loans identified in the related LSA Assignment as being less desirable or valuable than other comparable Loans originated or acquired by the Originator; and such Loans collectively shall be representative of the Originator’s portfolio of Loans; and

(v) all conditions precedent to any advance of a Borrowing to be made by the Initial Noteholder pursuant to the Note Purchase Agreement shall have been fulfilled as of such date.

(d) Subject to Section 6.07 , the parties hereto intend that each of the conveyances contemplated hereby be sales from the Originator to the Depositor of all of the Originator’s right, title and interest in and to the Assigned Assets and other property described above. In the event the transactions set forth herein are deemed not to be a sale, the Originator hereby grants to the Depositor a security interest in all of the Originator’s right, title and interest in, to and under the Assigned Assets, whether now existing or hereafter created, to secure all of the Originator’s obligations hereunder, and this Agreement shall constitute a security agreement under applicable law.

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Section 2.02 Obligations of Originator .

(a) On or prior to the Closing Date and each Transfer Date, as applicable, the Initial Noteholder shall have received evidence satisfactory to it of (i) the completion of all recordings, registrations and filings as may be necessary or, in the opinion of the Initial Noteholder, reasonably desirable to perfect or evidence the assignment by the Originator to the Depositor of the Originator’s ownership interest in the applicable Assigned Assets to be assigned to the Depositor on such date, including, without limitation, the applicable Transferred Loans and Related Property and other collateral constituting part of the Assigned Assets with respect to such Transferred Loans, (ii) the completion of all recordings, registrations and filings as may be necessary or, in the opinion of the Initial Noteholder, reasonably desirable to perfect or evidence the assignment by the Depositor to the Issuer of the Depositor’s ownership interest in the Assigned Assets and (iii) the completion of all recordings, registrations and filings as may be necessary or, in the opinion of the Initial Noteholder, reasonably desirable to perfect or evidence the grant of a first priority perfected security interest in the Assigned Assets in favor of the Indenture Trustee as Collateral pursuant to the Indenture. The Originator agrees to file all UCC-1 financing statements (and all continuation statements and amendments thereto) necessary to perfect the interest of the Depositor and the Issuer and the Indenture Trustee in and to the Assigned Assets and to take such other action as may be necessary or, in the opinion of the Depositor or the Initial Noteholder, desirable to perfect or evidence the Depositor’s, the Issuer’s and Indenture Trustee’s interest in the Assigned Assets conveyed under the Basic Documents.

(b) In connection with each sale and contribution of a Transferred Loan hereunder, the Originator shall deliver to, and deposit with the Collateral Custodian, as the designated agent of the Indenture Trustee, as assignee of the Depositor and the Issuer, on or b