FOURTH   SUPPLEMENTAL   INDENTURE,   dated  as  of  March  12,   2001  (the
"Supplemental  Indenture")  between Outsourcing  Solutions,  Inc., a corporation
organized under the laws of the State of Delaware (the "Company"),  and COAST TO
COAST CONSULTING,  LLC, a Delaware limited liability  company,  and PAE LEASING,
LLC, a Delaware limited liability company ("Additional  Guarantors") (as defined
below) and  Wilmington  Trust  Company  (the  "Trustee"),  as Trustee  under the
Indenture  (as defined  below).  Capitalized  terms used and not defined  herein
shall have the same meanings given in the Indenture unless otherwise indicated.

     WHEREAS, the Company, the Guarantors thereto and the Trustee are parties to
that certain Indenture dated as of November 6, 1996 (the  "Indenture")  pursuant
to which the Company issued its 11% Senior Subordinated Notes 2006 (the "Notes")
and the Guarantors guaranteed the obligations of the Company under the Indenture
and the Notes;

     WHEREAS, pursuant to Section 4.18 of the Indenture, if the Company acquires
or creates any additional subsidiary which is a domestic Restricted  Subsidiary,
each such subsidiary shall execute and deliver a supplemental indenture pursuant
to  which  such  subsidiary   shall   unconditionally   guaranty  the  Company's
obligations under the Notes;

     WHEREAS,  each  of  the  Additional  Guarantors  is a  domestic  Restricted
Subsidiary of the Company;

     WHEREAS,  the  Company  and  the  Trustee  desire  to have  the  Additional
Guarantors  enter into this  Supplemental  Indenture  and agree to guaranty  the
obligations  of the Company under the Indenture and the Notes and the Additional
Guarantors  desire to enter into the Supplemental  Indenture and to guaranty the
obligations of the Company under the Indenture and the Notes as of such date;

     WHEREAS,  Section  9.1 of the  Indenture  provides  that the  Company,  the
Guarantors  and the Trustee may,  without the written  consent of the holders of
the outstanding Notes, amend the Indenture as provided herein;

     WHEREAS, by entering into this Supplemental Indenture, the Company, and the
Trustee have  consented to amend the Indenture in accordance  with the terms and
conditions herein; and

     WHEREAS,  each  Guarantor  hereby  acknowledges  and  consents to amend the
Indenture in accordance with the terms and conditions herein;

     WHEREAS, all acts and things prescribed by the Certificate of Formation and
the Limited Liability Company Operating Agreement (each as now in effect) of the
Additional  Guarantors  necessary  to make this  Supplemental  Indenture a valid
instrument legally binding on the Additional  Guarantors for the purposes herein
expressed, in accordance with its terms, have been duly done and performed;

     NOW,  THEREFORE,  in  consideration of the foregoing and for other good and
valuable  consideration,  the  receipt  of which  is  hereby  acknowledged,  the
Company, the Additional  Guarantors and the Trustee hereby agree for the benefit
of each other and the equal and  ratable  benefit of the holders of the Notes as
follows:

     1. Additional Guarantors as Guarantors.  As of the date hereof and pursuant
to this Indenture  Supplement,  each of the Additional Guarantors shall become a
Guarantor  under clause (ii) of the  definition of Guarantor in the Indenture in
accordance  with the terms and  conditions of the Indenture and shall assume all
rights and obligations of a Guarantor thereunder.

     2.  Compliance  with and  Fulfillment  of  Condition of Section  4.18.  The
execution  and  delivery  of  this  Supplemental  Indenture  by  the  Additional
Guarantors (along with such documentation  relating thereto as the Trustee shall
require,  including,  without  limitation,  an  Opinion  of  Counsel  as to  the
enforceability  of the  Supplemental  Indenture  and an  Officer's  Certificate)
fulfills the obligations of the Company under Section 4.18 of the Indenture.

     3. Construction. For all purposes of this Supplemental Indenture, except as
otherwise herein expressly  provided or unless the context  otherwise  requires:
(i) the terms and  expressions  used  herein  shall  have the same  meanings  as
corresponding  terms and expressions  used in the Indenture;  and (ii) the words
"herein,"  "hereof" and "hereby" and other words of similar  import used in this
Supplemental  Indenture refer to this Supplemental  Indenture as a whole and not
to any particular Section hereof.

     4. Trustee  Acceptance.  The Trustee accepts the amendment of the Indenture
effected by this Supplemental  Indenture,  as hereby amended,  but only upon the
terms and conditions set forth in the Indenture,  as hereby  amended,  including
the  terms  and   provisions   defining  and  limiting   the   liabilities   and
responsibilities of the Trustee in the performance of its duties and obligations
under the Indenture,  as hereby amended.  Without limiting the generality of the
foregoing, the Trustee has no responsibility for the correctness of the recitals
of fact herein  contained  which shall be taken as the statements of each of the
Company   and  the   Additional   Guarantors,   respectively,   and   makes   no
representations as to the validity or enforceability  against any of the Company
or the Additional Guarantors.

     5. Indenture Ratified. Except as expressly amended hereby, the Indenture is
in all  respects  ratified  and  confirmed  and all the  terms,  conditions  and
provisions thereof shall remain in full force and effect.

     6. Holders  Bound.  This  Supplemental  Indenture  shall form a part of the
Indenture  for all  purposes,  and  every  holder  of the  Notes  heretofore  or
hereafter authenticated and delivered shall be bound hereby.

     7.  Successors and Assigns.  This  Supplemental  Indenture shall be binding
upon and  inure to the  benefit  of the  parties  hereto  and  their  respective
successors and assigns.

     8. Counterparts.  This Supplemental Indenture may be executed in any number
of  counterparts,  each of  which  when so  executed  shall be  deemed  to be an
original,  and all of such  counterparts  shall together  constitute one and the
same instrument.

     9.  Governing  Law. This  Supplemental  Indenture  shall be governed by and
construed in accordance  with the internal laws of the State of New York without
giving effect to principles of conflicts of laws.

<PAGE>
     IN WITNESS WHEREOF, the Company, the Additional  Guarantors and the Trustee
have caused this Supplemental Indenture to be duly executed as of the date first
above written.


               COMPANY:

               OUTSOURCING SOLUTIONS INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               ADDITIONAL GUARANTORS:

               COAST TO COAST CONSULTING, LLC

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Chairman


               PAE LEASING, LLC

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Chairman


               TRUSTEE:

               WILMINGTON TRUST COMPANY, not in its individual capacity but
               solely as trustee

               By:    /s/
                      ----------------------

               Title: Vice President
                      ----------------------


               ACKNOWLEDGED AND CONSENTED:

               OSI SUPPORT SERVICES, INC.
               (formerly known as Payco American Corporation)

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               OSI COLLECTION SERVICES, INC.
               (formerly known as Payco-General American Credits, Inc.)

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               OSI EDUCATION SERVICES, INC.
               (formerly known as University Accounting Service, Inc.)

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               JENNIFER LOOMIS & ASSOCIATES, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               ASSET RECOVERY & MANAGEMENT CORP.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               QUALINK, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               INDIANA MUTUAL CREDIT ASSOCIATION, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               GRABLE, GREINER & WOLFF, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               PROFESSIONAL RECOVERIES, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               PAYCO AMERICAN INTERNATIONAL CORP.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               OSI PORTFOLIO SERVICES, INC.
               (formerly known as Account Portfolios, Inc.)

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Chairman


               GULF STATE CREDIT, L.L.C.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Chairman


               PERIMETER CREDIT, L.L.C.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Chairman


               NORTH SHORE AGENCY, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Vice President


               THE UNION CORPORATION

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               OSI OUTSOURCING SERVICES, INC.
               (formerly known as Interactive Performance, Inc.)

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Chairman


               TRANSWORLD SYSTEMS, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Vice President


               UCO PROPERTIES, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               UNION SPECIALTY STEEL CASTING CORPORATION

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               UNION FINANCIAL SERVICES GROUP, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               AMERICAN RECOVERY COMPANY, INC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               C.S.N. CORP.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               GENERAL CONNECTOR CORPORATION

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               U.C.O.-M.B.A. CORPORATION

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               UNIVERSITY ACCOUNTING SERVICE, LLC

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: President


               RWC CONSULTING GROUP, LLC.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Chairman


               OSI OUTSOURCING SERVICES INTERNATIONAL, LTD.

               By:    /s/ Timothy G. Beffa
                      ----------------------
                      Timothy G. Beffa
               Title: Chairman of the Board


<PAGE>
                                    GUARANTEE
                                    ---------

     Coast  to  Coast  Consulting,  LLC (the  "Guarantor")  has  unconditionally
guaranteed on a senior basis (the  "Guarantee")  that the Principal of, interest
and Additional  Interest,  if any, on and any Additional  Amounts,  if any, with
respect to the Security upon which this  notation is endorsed,  will be duly and
punctually  paid in full when due,  whether  at  maturity,  by  acceleration  or
otherwise,  and interest on overdue  Principal,  and (to the extent permitted by
law) interest on any interest or Additional  Interest,  if any, on or Additional
Amounts, if any, with respect to the Securities and all other Obligations of the
Company to the  Holders or the Trustee  under the  Securities  or the  Indenture
(including fees, expenses or other Obligations) will be promptly paid in full or
performed.

     The  obligations  of the Guarantor to the Holders of Securities  and to the
Trustee pursuant to the Guarantee and the Indenture and the Second  Supplemental
Indenture  are  expressly  set forth,  and are senior  obligations  of each such
Guarantor  to the  extent  and in  the  manner  provided,  in  Article  X of the
Indenture,  and reference is made to such Indenture for the precise terms of the
Guarantee therein made.

     A trustee,  director,  officer, employee,  stockholder or incorporator,  as
such of the Guarantor  shall not have any liability for any  obligations  of the
Guarantor under the Securities, the Indenture, the Supplemental Indenture or the
Guarantee  or for any claim  based  on, in  respect  of, or by reason  of,  such
obligations or their  creation.  Each Holder by accepting a Security  waives and
releases  all  such   liability.   The  waiver  and  release  are  part  of  the
consideration for the issue of the Guarantee.

     All  capitalized  terms used but not defined  herein shall have the meaning
ascribed to them in the Security upon which this  notation is endorsed.  As used
herein  the  "Fourth  Supplemental  Indenture"  means  the  Fourth  Supplemental
Indenture,  dated  as of  March  12,  2001,  among  the  Company,  the  Original
Guarantors (as defined therein),  the Additional Guarantors (as defined therein)
and the Trustee.

     The Guarantee  shall not be valid or  obligatory  for any purpose until the
certificate  of  authentication  on the  Securities  upon which the Guarantee is
noted shall have been executed by the Trustee under the Indenture and the Fourth
Supplemental  Indenture  by the  manual  signature  of  one  of  its  authorized
officers.

               Guarantor:    Coast to Coast Consulting, LLC

               By:           /s/ Timothy G. Beffa
                             ------------------------------

               Name:         Timothy G. Beffa

               Title:        Chairman



<PAGE>
                                    GUARANTEE
                                    ---------

     PAE Leasing,  LLC (the  "Guarantor")  has  unconditionally  guaranteed on a
senior basis (the  "Guarantee")  that the Principal of,  interest and Additional
Interest,  if any, on and any  Additional  Amounts,  if any, with respect to the
Security upon which this notation is endorsed,  will be duly and punctually paid
in full when due,  whether  at  maturity,  by  acceleration  or  otherwise,  and
interest on overdue Principal,  and (to the extent permitted by law) interest on
any interest or Additional  Interest,  if any, on or Additional Amounts, if any,
with respect to the Securities  and all other  Obligations of the Company to the
Holders or the Trustee under the  Securities or the Indenture  (including  fees,
expenses or other Obligations) will be promptly paid in full or performed.

     The  obligations  of the Guarantor to the Holders of Securities  and to the
Trustee pursuant to the Guarantee and the Indenture and the Second  Supplemental
Indenture  are  expressly  set forth,  and are senior  obligations  of each such
Guarantor  to the  extent  and in  the  manner  provided,  in  Article  X of the
Indenture,  and reference is made to such Indenture for the precise terms of the
Guarantee therein made.

     A trustee,  director,  officer, employee,  stockholder or incorporator,  as
such of the Guarantor  shall not have any liability for any  obligations  of the
Guarantor under the Securities, the Indenture, the Supplemental Indenture or the
Guarantee  or for any claim  based  on, in  respect  of, or by reason  of,  such
obligations or their  creation.  Each Holder by accepting a Security  waives and
releases  all  such   liability.   The  waiver  and  release  are  part  of  the
consideration for the issue of the Guarantee.

     All  capitalized  terms used but not defined  herein shall have the meaning
ascribed to them in the Security upon which this  notation is endorsed.  As used
herein  the  "Fourth  Supplemental  Indenture"  means  the  Fourth  Supplemental
Indenture,  dated  as of  March  12,  2001,  among  the  Company,  the  Original
Guarantors (as defined therein),  the Additional Guarantors (as defined therein)
and the Trustee.

     The Guarantee  shall not be valid or  obligatory  for any purpose until the
certificate  of  authentication  on the  Securities  upon which the Guarantee is
noted shall have been executed by the Trustee under the Indenture and the Fourth
Supplemental  Indenture  by the  manual  signature  of  one  of  its  authorized
officers.

               Guarantor:    PAE Leasing, LLC

               By:           /s/ Timothy G. Beffa
                             ------------------------------

               Name:         Timothy G. Beffa

               Title:        Chairman