<PAGE>   1
                                                                   EXHIBIT 10.27


--------------------------------------------------------------------------------
                                FIRST AMENDMENT
                                       TO
                  FOURTH AMENDED AND RESTATED CREDIT AGREEMENT
--------------------------------------------------------------------------------

     First Amendment dated as of December 1, 2000 to the Fourth Amended and
Restated Credit Agreement (the "Amendment"), by and among HPSC, INC., a Delaware
corporation (the "Borrower"), AMERICAN COMMERCIAL FINANCE COMPANY, a Delaware
corporation (the "Guarantor" or "ACFC"), FLEET NATIONAL BANK and the other
lending institutions listed on Schedule I to the Credit Agreement (as
hereinafter defined) (the "Banks"), and Fleet National Bank as agent for the
Banks (in such capacity, the "Agent"), amending certain provisions of the Fourth
Amended and Restated Credit Agreement dated as of May 12, 2000 (as amended and
in effect from time to time, the "Credit Agreement") by and among the Borrower,
the Guarantor, the Banks and the Agent. Terms not otherwise defined herein which
are defined in the Credit Agreement shall have the same respective meanings
herein as therein.

     WHEREAS, the Borrower and the Banks have agreed to modify certain terms and
conditions of the Credit Agreement as specifically set forth in this Amendment;

     NOW, THEREFORE, in consideration of the premises and the mutual agreements
contained herein and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

     ss1. AMENDMENT TO SECTION 1 OF THE CREDIT AGREEMENT.

     (a) Section 1.1 of the Credit Agreement is hereby amended by adding the
following new definitions in the appropriate alphabetical order:

     NEWCO. Collectively, HPSC Equipment Receivables 2000-1 LLC I and HPSC
Equipment Receivables 2000-1 LLC II, each a Delaware limited liability company
and wholly-owned subsidiary of the Borrower.

     NEWCO INDENTURE. The Indenture dated as of December 1, 2000 among Newco,
the Borrower, ACFC, an Indenture Trustee and certain other parties named
therein.

     NEWCO TRIGGER EVENT. Any event or condition identified as an "Event of
Default", an "Event of Servicing Termination" or any similar trigger event or
termination event in the Newco Facility Documents.

     NEWCO FACILITY DOCUMENTS. Collectively, the Newco Indenture, the Newco
Receivables Transfer Agreement and all other agreements, documents and
instruments entered into pursuant thereto or in connection therewith.

     NEWCO RECEIVABLES TRANSFER AGREEMENT. The Receivables Transfer Agreement
dated as of December 1, 2000 among Newco, the Borrower, ACFC and certain other
parties named therein.


<PAGE>   2
                                       -2-


     NEWCO TRANSFERRED ASSETS. The accounts, chattel paper, instruments, and
other assets related thereto, comprised in the Collateral which are sold or
otherwise transferred to Newco pursuant to the Newco Receivables Transfer
Agreement.

     (b) Section 1.1 of the Credit Agreement is hereby amended by deleting the
following definitions in their entirety and restating such definitions as
follows:

     SECURITIZATION SUBSIDIARIES. Together, Bravo, Capital and Newco.

     TRANSFERRED ASSETS. Collectively, the Bravo Transferred Assets, the Capital
Transferred Assets and the Newco Transferred Assets.

     (c) Section 1.1 of the Credit Agreement is hereby amended by deleting
clauses (xiv) and (xv) of the definition of "Eligible Accounts Receivable" and
replacing them with the following new clauses (xiv) and (xv):

(xiv) that have not been transferred to Bravo pursuant to the Bravo Purchase
Agreement, Capital pursuant to the Capital Purchase Agreement or Newco pursuant
to the Newco Receivables Transfer Agreement; (xv) that are not subject to any
lien or negative pledge pursuant to the Bravo Credit Agreement, the Capital
Lease-Receivables Purchase Agreement or the Newco Facility Documents;

     ss2. AMENDMENT TO SECTION 9.4 OF THE CREDIT AGREEMENT. Section 9.4 of the
Credit Agreement is hereby amended by deleting paragraph (h) thereof and
replacing it with the following new paragraph (h):

          (h) within 5 days of receipt of the same by the Borrower copies of the
     monthly settlement reports under the Bravo Facility Documents, the Capital
     Facility Documents and the Newco Facility Documents and from time to time
     if the Agent or any Bank so requests copies of (i) other reports delivered
     under the Bravo Facility Documents, the Capital Facility Documents and the
     Newco Facility Documents and (ii) other financial data and information with
     respect to the Borrower or any of its Subsidiaries;

     ss3. AMENDMENT TO SECTION 10.1 OF THE CREDIT AGREEMENT. Section 10.1 of the
Credit Agreement is hereby amended by deleting paragraph (1) thereof and
replacing it with the following new paragraph (1):

          (1) Indebtedness incurred by Bravo pursuant to the Bravo Facility
     Documents and Indebtedness incurred by Newco pursuant to the Newco Facility
     Documents; and

     ss4. AMENDMENT TO SECTION 10.2 OF THE CREDIT AGREEMENT. Section 10.2 of the
Credit Agreement is hereby amended by deleting paragraph (1) thereof and
replacing it with the following new paragraph (1):

          (1) liens granted by Bravo in connection with the Bravo Facility
     Documents and liens granted by Newco in connection with the Newco Facility
     Documents; and


<PAGE>   3
                                       -3-


     ss5. AMENDMENT TO SECTION 10.3 OF THE CREDIT AGREEMENT. Section 10.3 of the
Credit Agreement is hereby amended by deleting paragraph (f) thereof and
replacing it with the following new paragraph (f):

          (f) Investments consisting of the Guaranty, Investments by the
     Borrower in Subsidiaries of the Borrower existing on the Closing Date,
     Investments made pursuant to the Bravo Facility Documents, Investments in
     connection with the Capital Lease-Receivables Purchase Agreement and
     Investments in Newco pursuant to the Newco Facility Documents;

     ss6. AMENDMENT TO SECTION 10.5.2 OF THE CREDIT AGREEMENT. Section 10.5.2 of
the Credit Agreement is hereby amended by deleting Section 10.5.2 thereof and
replacing it with the following new Section 10.5.2:

               10.5.2 DISPOSITION OF ASSETS. The Borrower will not, and will not
          permit any of its Subsidiaries to, become a party to or agree to or
          effect any disposition of assets, other than the disposition of assets
          in the ordinary course of business, consistent with industry
          practices, PROVIDED, HOWEVER, that such disposition of assets in the
          ordinary course of business shall not include a transfer of a material
          amount of Customer Receivables without the prior written approval of
          the Banks. Notwithstanding the foregoing provisions of this ss10.5.2
          and so long as no Event of Default has occurred and is continuing, the
          Borrower and its Subsidiaries may dispose of assets pursuant to the
          Bravo Purchase Agreement, the Capital Lease-Receivables Purchase
          Agreement, the Bravo Lease Receivables Purchase Agreement, the Newco
          Receivables Transfer Agreement and the Sale Agreements; PROVIDED that
          the sum of (i) aggregate principal amount of Indebtedness outstanding
          under the Sale Agreements plus (ii) all other proceeds received by the
          Borrower under such Sale Agreements and not characterized as
          Indebtedness shall not in any event exceed $50,000,000.

     ss7. AMENDMENT TO SECTION 10.8 OF THE CREDIT AGREEMENT. Section 10.8 of the
Credit Agreement is hereby amended by deleting Section 10.8 thereof and
replacing it with the following new Section 10.8:

     10.8 OTHER DEBT. The Borrower will not, and will not permit any of its
Subsidiaries to, (a) amend, supplement or otherwise modify the terms of any
Subordinated Debt or prepay, redeem or repurchase any Subordinated Debt (other
than, so long as no Default or Event of Default exists or would result from any
such repurchase, repurchases of Subordinated Debt pursuant to Section 4.16 of
the Senior Subordinated Note Indenture that do not exceed (i) $250,000 in
principal amount (plus accrued interest), in the aggregate with respect to all
holders of Subordinated Debt, in any calendar year or (ii) $25,000 in principal
amount (plus accrued interest), in the aggregate with respect to any single
holder of Subordinated Debt, in any calendar year) or (b) other than the
Securitization Subsidiaries, prepay, redeem or repurchase Indebtedness
outstanding under the Bravo Credit Agreement, the Capital Purchase Agreement,
the Newco Facility Documents or the Sale Agreements.


<PAGE>   4
                                      -4-


     ss8. AMENDMENT TO SECTION 14.1 OF THE CREDIT AGREEMENT. Section 14.1 of the
Credit Agreement is hereby amended by adding the following new paragraph (v)
after paragraph (u):

          or (v) the holders of all or any part of the Indebtedness under the
     Newco Facility Documents shall accelerate the maturity of all or any part
     of such Indebtedness or such Indebtedness shall be prepaid, redeemed or
     repurchased in whole or in part; or the occurrence of a Newco Trigger Event
     and the expiration of any applicable cure period available to Newco under
     the Newco Facility Documents;

     ss9. AMENDMENT TO SECTION 16.1 OF THE CREDIT AGREEMENT. Section 16.1 of the
Credit Agreement is hereby amended by adding the following sentence to the end
of paragraph (c) thereof:

Each of the Banks and the Agent acknowledge and agree that (i) the Agent is
authorized to release the security interest created by the Security Documents in
the Newco Transferred Assets and that (ii) the Agent is authorized to execute
and deliver, on behalf of the Banks and the Agent, such partial releases under
the Uniform Commercial Code as may be necessary or desirable to accomplish a
release of the security interest created by the Security Documents in the Newco
Transferred Assets.

     ss10. CONDITIONS TO EFFECTIVENESS. This Amendment shall not become
effective until the Agent receives (a) a counterpart of this Amendment, executed
by the Borrower, the Guarantor and each of the Banks, (b) a true and complete
copy of each of the Newco Facility Documents and (c) such other documents as the
Agent may request.

     ss11. REPRESENTATIONS AND WARRANTIES. The Borrower hereby repeats, on and
as of the date hereof, each of the representations and warranties made by it in
ss8 of the Credit Agreement, and such representations and warranties remain
true as of the date hereof (except to the extent of changes resulting from
transactions contemplated or permitted by the Credit Agreement and the other
Loan Documents, and to the extent that such representations and warranties
relate expressly to an earlier date), PROVIDED, that all references therein to
the Credit Agreement shall refer to such Credit Agreement as amended hereby. In
addition, the Borrower hereby represents and warrants that the execution and
delivery by the Borrower of this Amendment and the performance by the Borrower
of all of its agreements and obligations under the Credit Agreement as amended
hereby are within the corporate authority of the Borrower and has been duly
authorized by all necessary corporate action on the part of the Borrower.

     ss12. RATIFICATION, ETC. Except as expressly amended hereby, the Credit
Agreement, the Security Documents and all documents, instruments and agreements
related thereto are hereby ratified and confirmed in all respects and shall
continue in full force and effect. The Credit Agreement and this Amendment shall
be read and construed as a single agreement. All references in the Credit
Agreement or any related agreement or instrument to the Credit Agreement shall
hereafter refer to the Credit Agreement as amended hereby.


<PAGE>   5
                                       -5-


     ss13. NO WAIVER. Nothing contained herein shall constitute a waiver of,
impair or otherwise affect any Obligations, any other obligation of the Borrower
or any rights of the Agent or the Banks.

     ss14. COUNTERPARTS. This Amendment may be executed in one or more
counterparts, each of which shall be deemed an original but which together shall
constitute one and the same instrument.

     ss15. GOVERNING LAW. THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE COMMONWEALTH OF MASSACHUSETTS (WITHOUT
REFERENCE TO CONFLICT OF LAWS).


<PAGE>   6


                                       -6-

IN WITNESS WHEREOF, the undersigned have duly executed this Amendment as a
sealed instrument as of the date first set forth above.

                                        HPSC, INC.


                                        By: /s/ Rene Lefebvre
                                            ------------------------------------
                                            Name: RENE LEFEBVRE
                                            Title: VP, CFO

                                        FLEET NATIONAL BANK, individually and
                                        as Agent


                                        By: /s/ Harvey H. Thayer, Jr.
                                            ------------------------------------
                                            Name: HARVEY H. THAYER, JR.
                                            Title: MANAGING DIRECTOR

                                        KEYBANK NATIONAL ASSOCIATION


                                        By: /s/ Mitchell B. Feldman
                                            ------------------------------------
                                            Name: Mitchell B. Feldman
                                            Title: SVP

                                        NATIONAL BANK OF CANADA


                                        By: /s/ A. Keith Broyles
                                            ------------------------------------
                                            Name: A. Keith Broyles
                                            Title: Vice President & Manager


                                        By: /s/ Leonard J. [illegible]
                                            ------------------------------------
                                            Name: Leonard J. [illegible]
                                            Title: Vice President


<PAGE>   7
                                       -7-


                                        FIRST MASSACHUSETTS BANK, N.A.
                                        (f/k/a FAMILY BANK, FSB)


                                        By: /s/ Jon R. Sundstrom
                                            ------------------------------------
                                            Name: JON R. SUNDSTROM
                                            Title: SENIOR VICE PRESIDENT

                                        CITIZENS BANK OF MASSACHUSETTS


                                        By: /s/ Lune G. Bomms
                                            ------------------------------------
                                            Name: LUNE G. BOMMS
                                            Title: VICE PRESIDENT


<PAGE>   8
                                       -8-

                            RATIFICATION BY GUARANTOR

     The undersigned Guarantor hereby acknowledges and consents to the foregoing
Amendment as of December __, 2000 and agrees that the Guaranty dated as of June
23, 1994 from the undersigned in favor of the Agent and each of the Banks, as
amended by Omnibus Amendment No. 4 to Security Documents, dated as of May 12,
2000, and each of the other Security Documents to which it is a party remain in
full force and effect, and the Guarantor confirms and ratifies all of its
obligations thereunder.

                                        AMERICAN COMMERCIAL
                                        FINANCE CORPORATION


                                        By: /s/ John W. Everett
                                            ------------------------------------
                                            Name: John W. Everett
                                            Title: