<PAGE>

                                                                   Exhibit 10.49

                AMENDMENT NO. 6 TO CREDIT AND SECURITY AGREEMENT

            THIS AMENDMENT NO. 6 TO CREDIT AND SECURITY AGREEMENT (this
"Amendment") is entered into as of January 16, 2001, by and among:

            (1) SPHERION RECEIVABLES CORP., a Delaware corporation formerly
      known as Interim Services Receivables Corp. (together with its successors
      and permitted assigns, the "Borrower"),

            (2) SPHERION CORPORATION, a Delaware corporation formerly known as
      Interim Services Inc., as initial servicer (in such capacity, the
      "Servicer"),

            (3) BLUE RIDGE ASSET FUNDING CORPORATION, a Delaware corporation
      (together with its successors, "Blue Ridge"), FALCON ASSET SECURITIZATION
      CORPORATION, a Delaware corporation (together with its successors,
      "Falcon"), WACHOVIA BANK, N.A., a national banking association, in its
      capacity as a Liquidity Bank to Blue Ridge (together with its successors,
      "Wachovia"), and BANK ONE, NA, a national banking association having its
      main office in Chicago, Illinois and formerly known as "The First National
      Bank of Chicago," in its capacity as a Liquidity Bank to Falcon (together
      with its successors, "Bank One"), as Lenders,

            (4) WACHOVIA BANK, N.A., as administrative and liquidity agent for
      Blue Ridge and its Liquidity Banks (in such capacity, the "Blue Ridge
      Agent"), and BANK ONE, NA [MAIN OFFICE CHICAGO], as administrative and
      liquidity agent for Falcon and its Liquidity Banks (in such capacity, the
      "Falcon Agent" and, together with the Blue Ridge Agent, the "Co-Agents"),
      and

            (5) WACHOVIA BANK, N.A., as collateral agent for the Agents and the
      Lenders (in such capacity, together with any successors thereto in such
      capacity, the "Collateral Agent"),

with respect to that certain Credit and Security Agreement dated as of July 1,
1999, by and among the Borrower, the Servicer, the Lenders, the Co-Agents and
the Collateral Agent (as previously amended, the "Existing Agreement" which, as
amended hereby, is hereinafter referred to as the "Agreement").

            Unless otherwise indicated, capitalized terms used in this Amendment
are used with the meanings attributed thereto in the Existing Agreement.

<PAGE>

                                                                   Exhibit 10.49

                              W I T N E S S E T H :

            WHEREAS, the parties hereto desire to amend the Existing Agreement
      as hereinafter set forth;

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

            1. Amendments to Existing Agreement. Upon execution of this
Amendment by all parties hereto and payment by the Borrower to the Falcon Agent
of $ 96,761,077.01 in immediately available funds not later than 12:00 noon
(Chicago time) on January 16, 2001, the parties hereby agree that the Existing
Agreement is amended as follows:

            (a) the Commitment and Percentage of Bank One are hereby reduced to
      $0 and 0%, respectively, and the Falcon Agent acknowledges payment in full
      of all Obligations owing to Falcon, the Falcon Agent and Bank One,

            (b) Falcon and Bank One, individually and as Falcon Agent, shall
      cease to be parties to the Agreement and any references in the Agreement
      to the Co-Agents or the Falcon Agent shall thereafter be deemed to be
      references to the Blue Ridge Agent,

            (c) the Commitment and Percentage of Wachovia are hereby increased
      to $250,000,000 and 100%, respectively, and

            (d) the Reporting Date for the month of January 2001 is hereby
      changed to January 26, 2001.

            2. Representations.

            2.1. Each of the Loan Parties represents and warrants to the Lenders
and the Agents that it has duly authorized, executed and delivered this
Amendment and that the Agreement constitutes a legal, valid and binding
obligation of such Loan Party, enforceable in accordance with its terms (except
as enforceability may be limited by applicable bankruptcy, insolvency, or
similar laws affecting the enforcement of creditors' rights generally or by
equitable principles relating to enforceability).

            2.2. Each of the Loan Parties further represents and warrants to the
Lenders and the Agents that each of its representations and warranties set forth
in Section 6.1 of the Agreement is true and correct as of the date hereof and
that no Event of Default or Unmatured Default exists as of the date hereof and
is continuing except for the Event of Default under Section 10.1(f) that
occurred for the monthly reporting period ending October 29, 2000, which Event
of Default will be addressed by the Blue Ridge Agent separately after this
Amendment takes effect.

            3. Conditions Precedent. This Amendment shall become effective as of
the date first above written upon receipt by the Collateral Agent of (a) a
counterpart hereof duly


                                       2
<PAGE>

                                                                   Exhibit 10.49

executed by each of the parties hereto and (b) confirmation from the Falcon
Agent that it has received the funds required under Section 1 of this Amendment
by the date and time specified therein.

            4. Miscellaneous.

            4.1. Except as expressly amended hereby, the Existing Agreement
shall remain unaltered and in full force and effect, and each of the parties
hereby ratifies and confirms the Agreement and each of the other Transaction
Documents to which it is a party.

            4.2. THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF NEW YORK WITHOUT REFERENCE TO
PRINCIPLES OF CONFLICTS OF LAW.

            4.3. EACH LOAN PARTY HEREBY ACKNOWLEDGES AND AGREES THAT:

            4.3.1. IT IRREVOCABLY (i) SUBMITS TO THE NON-EXCLUSIVE JURISDICTION,
      FIRST, OF ANY UNITED STATES FEDERAL COURT, AND SECOND, IF FEDERAL
      JURISDICTION IS NOT AVAILABLE, OF ANY NEW YORK STATE COURT, IN EITHER CASE
      SITTING IN NEW YORK COUNTY, NEW YORK, IN ANY ACTION OR PROCEEDING ARISING
      OUT OF OR RELATING TO THE AGREEMENT, AND (ii) WAIVES, TO THE FULLEST
      EXTENT IT MAY EFFECTIVELY DO SO, THE DEFENSE OF AN INCONVENIENT FORUM TO
      THE MAINTENANCE OF AN ACTION OR PROCEEDING IN SUCH COURTS.

            4.3.2. TO THE EXTENT THAT IT HAS OR HEREAFTER MAY ACQUIRE ANY
      IMMUNITY FROM THE JURISDICTION OF ANY COURT OR FROM ANY LEGAL PROCESS
      (WHETHER THROUGH SERVICE OR NOTICE, ATTACHMENT PRIOR TO JUDGMENT,
      ATTACHMENT IN AID TO EXECUTION, EXECUTION OR OTHERWISE) WITH RESPECT TO
      ITSELF OR ITS PROPERTY, IT HEREBY IRREVOCABLY WAIVES SUCH IMMUNITY IN
      RESPECT OF ITS OBLIGATIONS UNDER OR IN CONNECTION WITH THE AGREEMENT.

            4.4. This Amendment may be executed in any number of counterparts
and by the different parties hereto in separate counterparts, each of which when
so executed shall be deemed to be an original and all of which when taken
together shall constitute one and the same Amendment.

                            (Signature pages follow)


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<PAGE>

                                                                   Exhibit 10.49

            IN WITNESS WHEREOF, the parties hereto have executed this Amendment
as of the date first above written.

BORROWER:
                        SPHERION RECEIVABLES CORP.


                        By: /s/ James W. Williamson
                            -----------------------
                            Name:  James W. Williamson
                            Title: Vice President (Risk Management)

SERVICER:
                        SPHERION CORPORATION


                        By: /s/ James W. Williamson
                            -----------------------
                            Name:  James Williamson
                            Title: Vice President (Risk Management)


                                        4
<PAGE>

                                                                   Exhibit 10.49

BORROWER:
                              SPHERION RECEIVABLES CORP.


                              By: /s/ James W. Williamson
                                  -----------------------
                                  Name:  James W. Williamson
                                  Title: Vice President (Risk Management)

SERVICER:
                              SPHERION CORPORATION


                              By:  /s/ James W. Williamson
                                   -------------------------
                                   Name:  James W. Williamson
                                   Title: Vice President (Risk Management)

AGENTS:

                              WACHOVIA BANK, N.A., as Collateral Agent and Blue
                              Ridge Agent


                              By: /s/ Kenny Karpowicz
                                  -------------------
                                  Name:  Kenny Karpowicz
                                  Title: Vice President


                              BANK ONE, NA, as Falcon Agent


                              By: /s/ Julie C. Benda
                                  ------------------
                                  Name:  Julie C. Benda
                                  Title: Vice President


                                        5
<PAGE>

                                                                   Exhibit 10.49

LENDERS:

                              BLUE RIDGE ASSET FUNDING CORPORATION

                              BY:  WACHOVIA BANK, N.A., ITS ATTORNEY-IN-FACT


                              By: /s/ Elizabeth R. Wagner
                                  -----------------------
                                  Name:  Elizabeth R. Wagner
                                  Title: Senior Vice President

                                  Commitment: not applicable
                                  Percentage: not applicable

                              WACHOVIA BANK, N.A.


                              By: /s/ Kenny Karpowicz
                                  -------------------
                                  Name:  Kenny Karpowicz
                                  Title: Vice President

                                  Commitment: $250,000,000
                                  Percentage: 100%


                                        6
<PAGE>

                                                                   Exhibit 10.49

                              FALCON ASSET SECURITIZATION CORPORATION


                              By: /s/ Julie C. Benda
                                  ------------------
                                  Name: Julie C. Benda
                                  Title: Authorized Signatory

                                  Commitment: not applicable
                                  Percentage: not applicable


                              BANK ONE, NA


                              By: /s/ Julie C. Benda
                                  ------------------
                                  Name: Julie C. Benda
                                  Title: Vice President

                                  Commitment: $0
                                  Percentage: 0%


                                       7