<PAGE>   1

                                                                  EXHIBIT 10.18



                      AMENDMENT NO. 1 TO CREDIT AGREEMENT


         THIS AMENDMENT NO. 1 TO CREDIT AGREEMENT (this "Amendment No. 1"),
dated as of December 18, 1996, is entered into by and among PERSONNEL GROUP OF
AMERICA, INC. (the "Borrower"), CERTAIN SUBSIDIARIES OF THE BORROWER IDENTIFIED
ON THE SIGNATURES PAGES HERETO (the "Guarantors"), NATIONSBANK, N.A. (the
"Existing Lender"), THE PERSONS IDENTIFIED AS A "NEW LENDER" ON THE SIGNATURE
PAGES HERETO (the "New Lenders" and, together with the Existing Lender, the
"Lenders") and NATIONSBANK, N.A., as agent for the Lenders (in such capacity,
the "Agent").

                                    RECITALS

         WHEREAS, the Borrower, the Guarantors, the Existing Lender and the
Agent entered into that certain Credit Agreement dated as of September 30, 1996
(the "Existing Credit Agreement");

         WHEREAS, the parties hereto have agreed to amend the Existing Credit
Agreement as set forth herein;

         NOW, THEREFORE, in consideration of the agreements herein contained,
the parties hereby agree as follows:


                                     PART I
                                   DEFINITIONS

                  SUBPART 1.1. Certain Definitions. Unless otherwise defined 
herein or the context otherwise requires, the following terms used in this
Amendment No. 1, including its preamble and recitals, have the following
meanings:

                  "Amended Credit Agreement" means the Existing Credit Agreement
         as amended hereby.

                  "Amendment No. 1 Effective Date" is defined in Subpart 3.1.

                  SUBPART 1.2. Other Definitions. Unless otherwise defined 
herein or the context otherwise requires, terms used in this Amendment No. 1,
including its preamble and recitals, have the meanings provided in the Amended
Credit Agreement.




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<PAGE>   2



                                     PART II
                     AMENDMENTS TO EXISTING CREDIT AGREEMENT

         Effective on (and subject to the occurrence of) the Amendment No. 1
Effective Date, the Existing Credit Agreement is hereby amended in accordance
with this Part II. Except as so amended, the Existing Credit Agreement and all
other Credit Documents shall continue in full force and effect.

         SUBPART 2.1. Amendment to Section 1.1. The definition of "Borrower's
Obligations" set forth in Section 1.1 of the Existing Credit Agreement is
amended in its entirety to read as follows:

                  "Borrower's Obligations" means, without duplication, (i) all
         of the obligations of the Borrower to the Lenders (including the
         Issuing Lender) and the Agent, whenever arising, under the Credit
         Agreement, the Notes or any of the other Credit Documents (including,
         but not limited to, any interest accruing after the occurrence of a
         Bankruptcy Event with respect to the Borrower, regardless of whether
         such interest is an allowed claim under the Bankruptcy Code) and (ii)
         all liabilities and obligations, whenever arising, owing from the
         Borrower to any Lender, or any Affiliate of a Lender, arising under any
         Hedging Agreement.

         SUBPART 2.2. Amendment to Section 2.1(a).  Section 2.1(a) of the
Existing Credit Agreement is amended in its entirety to read as follows:

         2.1 Loans.

                  (a) Commitment. Subject to the terms and conditions hereof and
         in reliance upon the representations and warranties set forth herein,
         each Lender severally agrees to make available to the Borrower such
         Lender's Commitment Percentage of revolving credit loans requested by
         the Borrower in Dollars ("Loans") from time to time from the Closing
         Date until the Termination Date, or such earlier date as the
         Commitments shall have been terminated as provided herein for the
         purposes hereinafter set forth; provided, however, that the sum of the
         aggregate principal amount of outstanding Loans shall not exceed ONE
         HUNDRED TWENTY-FIVE MILLION DOLLARS ($125,000,000) (as such aggregate
         maximum amount may be reduced from time to time as provided in Section
         3.4, the "Committed Amount") ; provided, further, (i) with regard to
         each Lender individually, such Lender's outstanding Loans shall not
         exceed such Lender's Commitment Percentage of the Committed Amount, and
         (ii) with regard to the Lenders collectively, the aggregate principal
         amount of outstanding Loans plus LOC Obligations outstanding shall not
         exceed the Committed Amount. Loans may consist of Base Rate Loans or
         Eurodollar Loans, or a combination thereof, as the Borrower may
         request, and may be repaid and reborrowed in accordance with the
         provisions hereof; provided, however, that (x) during the Initial
         Interest Rate Period, all Eurodollar Loans shall have an Interest


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         Period of one (1) month and (y) no more than 7 Eurodollar Loans shall
         be outstanding hereunder at any time. For purposes hereof, Eurodollar
         Loans with different Interest Periods shall be considered as separate
         Eurodollar Loans, even if they begin on the same date, although
         borrowings, extensions and conversions may, in accordance with the
         provisions hereof, be combined at the end of the existing Interest
         Periods to constitute a new Eurodollar Loan with a single Interest
         Period. Loans hereunder may be repaid and reborrowed in accordance with
         the provisions hereof.

         SUBPART 2.3. Amendments to Schedule 2.1(a). Schedule 2.1(a) of the
Existing Credit Agreement is hereby deleted in its entirety and a new schedule
in the form of Schedule 2.1(a) attached hereto is substituted therefor.


                                    PART III
                           ASSIGNMENTS AND ASSUMPTIONS

         The Existing Lender hereby sells and assigns, without recourse, to the
New Lenders, and the New Lenders hereby purchase and assume, without recourse,
from the Existing Lender, effective as of the Amendment No. 1 Effective Date,
such interests in the Existing Lender's rights and obligations under the
Existing Credit Agreement (including, without limitation, the Commitments of the
Existing Lender on the Amendment No. 1 Effective Date and the Loans and LOC
Obligations which are outstanding on the Amendment No. 1 Effective Date) as
shall be necessary in order to give effect to the reallocations of the Committed
Amounts and Commitment Percentages effected by the amendments to the Existing
Credit Agreement pursuant to Part II. The Existing Lender and each of the New
Lenders hereby makes and agrees to be bound by all the representations,
warranties and agreements set forth in Section 11.3(b) of the Amended Credit
Agreement. From and after the Amendment No. 1 Effective Date (i) each of the New
Lenders shall be a party to and be bound by the provisions of the Amended Credit
Agreement and, to the extent of the interests assigned hereby, have the rights
and obligations of a Lender thereunder and under the other Credit Documents and
(ii) the Existing Lender shall, to the extent of the interests assigned hereby,
relinquish its rights and be released from its obligations under the Existing
Credit Agreement. The Agent shall record in the register referred to in Section
11.3(c) of the Amended Credit Agreement on the Amendment No. 1 Effective Date
the information relating to the assignments and assumptions effected pursuant to
this Part III. The Agent hereby agrees (i) that no transfer fee shall be payable
under Section 11.3(b) of the Existing Credit Agreement or otherwise in
connection with the assignments effected pursuant to this Part III and (ii) to
pay to each New Lender its portion of the Upfront Fee as separately agreed to by
the Agent and such New Lender.



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<PAGE>   4



                                     PART IV
                           CONDITIONS TO EFFECTIVENESS

         SUBPART 4.1. Amendment No. 1 Effective Date. This Amendment No. 1 shall
be and become effective as of the date hereof (the "Amendment No. 1 Effective
Date") when all of the conditions set forth in this Subpart 4.1 shall have been
satisfied, and thereafter this Amendment No. 1 shall be known, and may be
referred to, as "Amendment No. 1."

         SUBPART 4.1.1. Execution of Counterparts of Amendment. The Agent shall
have received executed counterparts (or other evidence of execution, including
facsimile signatures, satisfactory to the Agent) of this Amendment No. 1, which
collectively shall have been duly executed on behalf of each of the Borrower,
the Guarantors, the Lenders and the Agent.

         SUBPART 4.1.2. Execution of Notes. The Agent shall have received an
appropriate original Note for each Lender (but, in the case of the new Note to
the Existing Lender, with notation thereon that it is given in substitution for
and replacement of the original Note or any replacement notes thereof).

         SUBPART 4.1.3. Corporate Authority. The Agent shall have received all
documents it may reasonably request relating to the corporate or other necessary
authority for the execution, delivery and performance of this Amendment No. 1.

         SUBPART 4.1.4. Other Documents. The Agent shall have received such
other documents as the Agent, the Lender or counsel to the Agent may reasonably
request.


                                     PART V
                                  MISCELLANEOUS

         SUBPART 5.1. Cross-References. References in this Amendment No. 1 to
any Part or Subpart are, unless otherwise specified, to such Part or Subpart of
this Amendment No. 1.

         SUBPART 5.2. Instrument Pursuant to Existing Credit Agreement. This
Amendment No. 1 is a Credit Document executed pursuant to the Existing Credit
Agreement and shall (unless otherwise expressly indicated therein) be construed,
administered and applied in accordance with the terms and provisions of the
Existing Credit Agreement.

         SUBPART 5.3. References in Other Credit Documents. At such time as this
Amendment No. 1 shall become effective pursuant to the terms of Subpart 3.1, all
references in the Credit Documents to the "Credit Agreement" shall be deemed to
refer to the Amended Credit Agreement.

         SUBPART 5.4. Representations and Warranties. Each Credit Party hereby
represents and warrants that (i) each Credit Party that is party to this
Amendment No. 1: (a) has the requisite corporate power and authority to execute,
deliver and perform this Amendment No. 1, as 


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applicable and (b) is duly authorized to, and has been authorized by all
necessary corporate action, to execute, deliver and perform this Amendment No.
1, (ii) the Borrower has no claims, counterclaims, offsets, or defenses to the
Credit Documents and the performance of its obligations thereunder, or if the
Borrower has any such claims, counterclaims, offsets, or defenses to the Credit
Documents or any transaction related to the Credit Documents, the same are
hereby waived, relinquished and released in consideration of the Lender's
execution and delivery of this Amendment No. 1, (iii) the representations and
warranties contained in Section 6 of the Existing Credit Agreement are, subject
to the limitations set forth therein, true and correct in all material respects
on and as of the date hereof as though made on and as of such date (except for
those which expressly relate to an earlier date) and (iv) no Default or Event of
Default exists under the Existing Credit Agreement on and as of the date hereof
or will occur as a result of the transactions contemplated hereby.

         SUBPART 5.5. Liens. The Borrower and the Guarantors, as applicable,
affirm the liens and security interests created and granted in the Credit
Documents and agree that this Amendment No. 1 shall in no manner adversely
effect or impair such liens and security interest.

         SUBPART 5.6. Acknowledgement of Guarantors. The Guarantors acknowledge
and consent to all of the terms and conditions of this Amendment No. 1 and agree
that this Amendment No. 1 and all documents executed in connection herewith do
not operate to reduce or discharge the Guarantors' obligations under the Amended
Credit Agreement or the other Credit Documents. The Guarantors further
acknowledge and agree that the Guarantors have no claims, counterclaims,
offsets, or defenses to the Credit Documents and the performance of the
Guarantors' obligations thereunder or if the Guarantors did have any such
claims, counterclaims, offsets or defenses to the Credit Documents or any
transaction related to the Credit Documents, the same are hereby waived,
relinquished and released in consideration of the Lenders' execution and
delivery of this Amendment No. 1.

         SUBPART 5.7. No Other Changes. Except as expressly modified and amended
in this Amendment No. 1, all the terms, provisions and conditions of the Credit
Documents shall remain unchanged.

         SUBPART 5.8. Counterparts. This Amendment No. 1 may be executed by the
parties hereto in several counterparts, each of which shall be deemed to be an
original and all of which shall constitute together but one and the same
agreement.

         SUBPART 5.9. Entirety. This Amendment No. 1, the Amended Credit
Agreement and the other Credit Documents embody the entire agreement between the
parties and supersede all prior agreements and understandings, if any, relating
to the subject matter hereof. These Credit Documents represent the final
agreement between the parties and may not be contradicted by evidence of prior,
contemporaneous or subsequent oral agreements of the parties.



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         SUBPART 5.10. Governing Law. THIS AMENDMENT NO. 1 AND THE RIGHTS AND
OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE GOVERNED BY AND CONSTRUED AND
INTERPRETED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NORTH CAROLINA.

         SUBPART 5.11. Successors and Assigns. This Amendment No. 1 shall be
binding upon and inure to the benefit of the parties hereto and their respective
successors and assigns.






                             [Signatures to Follow]









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<PAGE>   7



         This Amendment No. 1 is executed as of the day and year first written
above.

BORROWER:                           PERSONNEL GROUP OF AMERICA, INC.,
                                    a Delaware corporation

                                    By: /s/ Ken Bramlett
                                        ----------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Senior Vice President
                                          -----------------------------------


GUARANTORS:                         STAFFPLUS, INC.,
                                    a Delaware corporation

                                    By:  /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------  



                                    THOMAS STAFFING SERVICES, INC.,
                                    a California corporation

                                    By: /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------


                                    PFI CORP.,
                                    a Delaware corporation

                                    By: /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President 
                                          -----------------------------------
                                           


                                    NURSEFINDERS, INC.,
                                    a Texas corporation

                                    By: /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------





                         [Guarantor Signatures Continue]


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                                    NF SERVICES, INC.,
                                    a New York corporation

                                    By: /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------


                                    B.C.P., INC.,
                                    a Hawaii corporation
 
                                    By: /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------


                                    PROFILE TEMPORARY SERVICES, INC.,
                                    an Illinois corporation


                                    By: /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------


                                    INFOTECH SERVICES, INC.,
                                    a North Carolina corporation


                                    By: /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------


                                    BROUGHTON SYSTEMS, INC.,
                                    a Virginia corporation


                                    By: /s/ Ken Bramlett
                                       --------------------------------------
                                    Name:  Ken Bramlett
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------



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EXISTING LENDER:                    NATIONSBANK, N.A.,
                                    individually in its capacity as a Lender 
                                    and in its capacity as Agent

                                    By:  /s/ Mark D. Halmrast
                                       --------------------------------------
                                    Name:  Mark D. Halmrast
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------



NEW LENDERS:                        BANK OF AMERICA, ILLINOIS


                                    By:  /s/ Richard E. Bryson
                                       --------------------------------------
                                    Name:  Richard E. Bryson
                                         ------------------------------------
                                    Title: Managing Director
                                          -----------------------------------



                                    BANQUE PARIBAS


                                    By:  /s/ Duane P. Helkowski
                                       --------------------------------------
                                    Name:  Duane P. Helkowski
                                         ------------------------------------
                                    Title: Assistant Vice President
                                          -----------------------------------

                                    By:  /s/ John J. McCormick, III
                                       --------------------------------------
                                    Name:  John J. McCormick, III
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------



                                    COMERICA BANK


                                    By:  /s/ Tamara J. Gurne
                                       --------------------------------------
                                    Name:  Tamara J. Gurne
                                         ------------------------------------
                                    Title: Account Officer
                                          -----------------------------------


                                    CREDIT LYONNAIS ATLANTA AGENCY


                                    By:  /s/ David M. Cawrse
                                       --------------------------------------
                                    Name:  David M. Cawrse
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------


                          [Lender Signatures Continue]





                                      S-3


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                                    THE FIRST NATIONAL BANK OF CHICAGO


                                    By:  /s/ William J. Oleferchik
                                       --------------------------------------
                                    Name:  William J. Oleferchik
                                         ------------------------------------
                                    Title: Authorized Agent
                                          -----------------------------------


                                    PNC BANK, NATIONAL ASSOCIATION


                                    By:  /s/ Robert J. Mitchell, Jr.
                                       --------------------------------------
                                    Name: Robert J. Mitchell, Jr.
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------


                                    UNITED STATES NATIONAL BANK OF OREGON

                                    By:  /s/ J. Stephen Mitchell
                                       --------------------------------------
                                    Name:  J. Stephen Mitchell
                                         ------------------------------------
                                    Title: Vice President
                                          -----------------------------------



                                      S-4