<PAGE>
 
                                                                 10. (i) (G) (7)
                                                                                



                                   WAIVER TO
                                        
                   POST-PETITION LOAN AND GUARANTY AGREEMENT



          WAIVER TO POST-PETITION LOAN AND GUARANTY AGREEMENT, dated as of
September 2, 1998 (this "Waiver"), among MONTGOMERY WARD & CO., INCORPORATED, an
Illinois corporation and a debtor and debtor in possession ("Borrower
Representative"), MONTGOMERY WARD HOLDING CORP., a Delaware corporation and a
debtor and debtor in possession ("Parent" or "Guarantor"), as Guarantor, the
other Guarantors signatory hereto (together with Parent and the Borrower
Representative, the "Credit Parties"), GENERAL ELECTRIC CAPITAL CORPORATION, a
New York corporation (in its individual capacity, "GE Capital"), for itself, as
Lender, and as Agent (the "Agent") for Lenders, and the other Lenders signatory
hereto.


                                   RECITALS
                                   --------


          WHEREAS, the Borrower Representative, the Guarantors, the Lenders and
the Agent are parties to that certain Post-Petition Loan and Guaranty Agreement,
dated as of July 8, 1997 (as amended by the Waiver and First Amendment to Post-
Petition Loan and Guaranty Agreement dated as of July 30, 1997, the Waiver and
Second Amendment to Post-Petition Loan and Guaranty Agreement dated as of
February 20, 1998, and as further amended, supplemented or modified, the "Loan
Agreement"). The Borrower Representative and the Guarantors have requested that
the Lenders agree to waive, for the limited purposes set forth herein, certain
provisions of the Loan Agreement. The Borrower Representative, the Guarantors,
the Lenders and the Agent have agreed, upon the terms and conditions specified
herein, to waive such provisions as hereinafter set forth.

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

          SECTION 1.  Defined Terms and Interpretation.

          (a) The capitalized terms used herein which are defined in the Loan
Agreement, shall have the respective meanings assigned to them in the Loan
Agreement except as otherwise provided herein or unless the context otherwise
requires.

          (b) Section headings in this Waiver are included herein for
convenience of reference only and shall not constitute a part of this Waiver for
any other purpose.

          (c) No provision in this Waiver shall be interpreted or construed
against any Person because that Person or its legal representative drafted such
provision.
<PAGE>
 
          SECTION 2.  Waiver.

          (a) As of the effective date of this Waiver, Lenders hereby waive the
provisions of Section 1.4 of the Loan Agreement, for the limited purpose of
permitting the Borrower Representative to pay certain prepetition real property
taxes and to compromise and settle governmental units' related claims pursuant
to that certain order approving the Motion of Debtors and Debtors in Possession
for an Order Authorizing Payment of Certain Prepetition Real Property Taxes and
Compromise and Settlement of Related Claims, dated July 24, 1998.

          (b) Pursuant to an Order of this Court, dated August 14, 1997, the
Debtors sold substantially all of the assets of Lechmere, Inc. ("Lechmere"), a
wholly-owned debtor subsidiary, the proceeds from which sale (the "Proceeds")
were required to be kept in a segregated account. Signature Financial/Marketing,
Inc. ("Signature"), a wholly-owned affiliate of the Debtors, is seeking a new
credit facility. The Debtors are seeking to authorize Lechmere to loan the
Proceeds to Signature on a secured basis, with the Borrower Representative to
guarantee such loan subordinated to the Obligations.

          (c) As of the effective date of this Waiver, Lenders hereby waive the
provisions of Sections 6.8 and 6.9 of the Loan Agreement as to Lechmere, and the
provisions of Sections 6.2 and 6.8 of the Loan Agreement as to the Borrower
Representative, for the limited purpose of permitting Lechmere to loan the
Proceeds to Signature on a secured basis, with the Borrower Representative to
guarantee the loan, subordinate only to the Loan Agreement, pursuant to that
certain order approving the Motion of Debtors and Debtors in Possession for an
Order Modifying Prior Order of Court and Authorizing Lechmere, Inc. to Loan
Money to Signature Financial/Marketing, Inc. Pursuant to Section 345 of the
Bankruptcy Code, dated August 13, 1998.

          SECTION 3. Representations and Warranties True; No Default or Event of
Default. The Credit Parties represent and warrant to the Agent and the Lenders
that on the date of and after giving effect to the execution and delivery of
this Waiver (a) the representations and warranties set forth in the Loan
Agreement are true and correct in all material respects on the date hereof as
though made on and as of such date (unless any such representation or warranty
expressly relates to an earlier date); and (b) neither any Default nor Event of
Default has occurred and is continuing as of the date hereof.


          SECTION 4.  Reference to this Waiver and Effect on Loan Documents.

          (a) From and after the date hereof, each reference in the Loan
Agreement (including in any Exhibit thereto) to "this Agreement," "hereunder,"
"herein" or words of like import shall mean and be a reference to the Loan
Agreement, as affected hereby.

          (b) From and after the date of this Waiver, each reference in the Loan
Documents to the Loan Agreement shall mean and be a reference to the Loan
Agreement, as affected hereby.

                                       2
<PAGE>
 
          (c) The Loan Agreement, the Notes and the other Loan Documents, as
affected hereby, shall remain in full force and effect and the Loan Documents
are hereby ratified and confirmed in all respects.

          (d) The effectiveness of the waiver evidenced by Section 2 hereof,
shall not, except as expressly provided herein, operate as a waiver of any
right, power or remedy of the Lenders or the Agent under the Loan Agreement, or
constitute a waiver of any other provision of the Loan Agreement or any other
Loan Document.

          SECTION 5. Effectiveness. This Waiver shall become effective upon
receipt by the Agent of executed counterparts of this Waiver from the requisite
number of Lenders that comprise the Requisite Lenders.

          SECTION 6. Governing Law; Binding Effect. In all respects, including
all matters of construction, validity and performance, this Waiver shall be
governed by, and construed and enforced in accordance with, the internal laws of
the State of New York (without regard to conflict of law provisions) and any
applicable laws of the United States of America, and shall be binding upon the
parties hereto and their respective successors and permitted assigns.

          SECTION 7. Execution in Counterparts. This Waiver may be executed in
any number of counterparts and by different parties hereto in separate
counterparts, each of which when so executed shall be deemed to be an original
and all of which taken together shall constitute one and the same agreement.

          SECTION 8. Consent of Guarantors. By their execution and delivery of
this Waiver, each Guarantor hereby consents to all of the terms and provisions
of this Waiver and ratifies and confirms that each of the Loan Documents to
which it is a party remains in full force and effect and enforceable in
accordance with their respective terms.

          IN WITNESS WHEREOF, this Waiver has been duly executed as of the date
first written above.



                    BORROWER:
 
                    MONTGOMERY WARD & CO., INCORPORATED
 

                    By:    /s/ Thomas J. Paup
                           --------------------------------------------
                    Name:  Thomas J. Paup
                    Title: Executive Vice President and Chief
                           Financial Officer

                                       3
<PAGE>

                    GUARANTORS:
                    
                    LECHMERE, INC.
                    
                    
                    By:    /s/ Don Civgin
                           --------------------------------------------
                    Name:  Don Civgin
                    Title: Vice President and Treasurer
                    
                    
                    AMERICAN DELIVERY SERVICE COMPANY
                    
                    
                    By:    /s/ Philip D. Delk
                           --------------------------------------------
                    Name:  Philip D. Delk
                    Title: Vice President, Secretary and Assistant
                           Treasurer
                    
                    
                    CONTINENTAL TRANSPORTATION, INC.
                    
                    
                    By:    /s/ Philip D. Delk
                           --------------------------------------------
                    Name:  Philip D. Delk
                    Title: Vice President, Secretary and Assistant
                           Treasurer
                    
                    
                    JRI DISTRIBUTING, INC.
                    STANDARD T CHEMICAL COMPANY, INC.
                    WFL REALTY, INC.
                    
                    
                    By:    /s/ Philip D. Delk
                           --------------------------------------------
                    Name:  Philip D. Delk
                    Title: Vice President and Secretary
                    
                    
                    M-W PRESTRESS, INC.
                    MW DIRECT GENERAL, INC.
                    MW DIRECT LIMITED, INC.
                    
                    
                    By:    /s/ Philip D. Delk
                           --------------------------------------------
                    Name:  Philip D. Delk
                    Title: Secretary

                                       4
<PAGE>
            
                    MONTGOMERY WARD INTERNATIONAL, INC.
                    MPI, INC.
            
            
                    By:    /s/ Philip D. Delk
                           --------------------------------------------
                    Name:  Philip D. Delk
                    Title: Assistant Secretary
            
            
                    BARRETWARD PROPERTIES CO., INC.
                    BRANDYWINE DC, INC.
                    BRANDYWINE PROPERTIES, INC.
                    BRETTWARD PROPERTIES CO., INC.
                    FIRST MONT CORPORATION
                    FOURTH WYCOMBE PROPERTIES, INC.
                    GABEWARD PROPERTIES CORPORATION
                    GARDEN GROVE DEVELOPMENT CORPORATION
                    HUGA REALTY INC.
                    JOSHWARD PROPERTIES CORPORATION
                    LECHMERE DEVELOPMENT CORPORATION
                    M-W FAIRFAX PROPERTIES, INC.
                    M-W PROPERTIES CORPORATION
                    M-W RESTAURANTS REALTY CORPORATION
                    MARCOR HOUSING SYSTEMS, INC.
                    MARYWARD PROPERTIES CORPORATION
                    MF NEVADA INVESTMENTS, INC.
                    MICHAELWARD PROPERTIES CO., INC.
                    MONTGOMERY WARD DEVELOPMENT CORPORATION
                    MONTGOMERY WARD LAND CORPORATION
                    MONTGOMERY WARD PROPERTIES CORPORATION
                    MONTGOMERY WARD REALTY CORPORATION
                    MW LAND CORPORATION
                    NATIONAL HOMEFINDING SERVICE, INC.
                    998 MONROE CORPORATION
                    PAULWARD PROPERTIES CO., INC.
                    ROBERTWARD PROPERTIES CORPORATION
                    SACWARD PROPERTIES, INC.
                    SECOND MONT CORPORATION
                    7TH & CARROLL CORPORATION
                    SEVENTH MONT CORPORATION
                    618 CORPORATION
                    619 CORPORATION
                    THE 535 CORPORATION
                    THIRD WYCOMBE PROPERTIES, INC.
                    2825 DEVELOPMENT CORPORATION
                    2825 REALTY CORPORATION

                                       5
<PAGE>
 
                    UNIVERSITY AVENUE MARKETPLACE, INC.
                    WFL DEVELOPMENT CORPORATION
                    WYCOMBE PROPERTIES, INC.
                  
                  
                    By:    /s/ G. Tad Morgan
                           --------------------------------------------
                    Name:  G. Tad Morgan
                    Title: Vice President and Secretary
                  
                  
                    GOODE FURNITURE COMPANIES, INC.
                    MONTGOMERY WARD SECURITIES, INC.
                    R M P DEVELOPMENT CORPORATION
                  
                  
                    By:    /s/ G. Tad Morgan
                           --------------------------------------------
                    Name:  G. Tad Morgan
                    Title: Secretary
                  
                  
                    MONTGOMERY WARD HOLDING CORP.
                  
                  
                    By:    /s/ G. Tad Morgan
                           --------------------------------------------
                    Name:  G. Tad Morgan
                    Title: Assistant Secretary
                  
                  
                    JEFFERSON STORES, INC.
                  
                  
                    By:    /s/ G. Tad Morgan
                           --------------------------------------------
                    Name:  G. Tad Morgan
                    Title: Vice President and Treasurer
                  
                  
                    AGENT and as LENDER
                  
                    GENERAL ELECTRIC CAPITAL CORPORATION
                  
                  
                    By:    /s/ Paul M. Feehan
                           --------------------------------------------
                    Name:  Paul M. Feehan
                    Title: Its Authorized Signatory

                                       6
<PAGE>
                     
                    LENDERS:
                                        
                    THE CHASE MANHATTAN BANK
                                        
                    By:    /s/ William P. Rindfuss
                           --------------------------------------------
                    Name:  William P. Rindfuss
                    Title: Vice President
                                        
                    
                    BANK OF SCOTLAND
                    
                    
                    By:    /s/ Annie Chin Tat
                           --------------------------------------------
                    Name:  Annie Chin Tat
                    Title: Senior Vice President
                                        
                    
                    BANKAMERICA BUSINESS CREDIT, INC.
                    
                    
                    By:    /s/ Thomas G. Sullivan
                           --------------------------------------------
                    Name:  Thomas G. Sullivan
                    Title: Vice President
                                        
                    
                    BANKBOSTON RETAIL FINANCE INC.
                     (f/k/a GBFC, INC.)
                                        
                    
                    By:    /s/ Mary E. Abbott
                           --------------------------------------------
                    Name:  Mary E. Abbott
                    Title: Assistant Vice President
                                        
                    
                    PARIBAS
                    
                    
                    By:    /s/ John J. McCormick III
                           --------------------------------------------
                    Name:  John J. McCormick III
                    Title: Vice President
                                        
                    By:    /s/ Duane Helkowski
                           --------------------------------------------
                    Name:  Duane Helkowski
                    Title: Vice President
                                        
                                                           7
<PAGE>
 
                    CREDIT AGRICOLE INDOSUEZ            
                                    
                                    
                    By:    /s/ David Bouhl
                           --------------------------------------------
                    Name:  David Bouhl, F.V.P.
                    Title: Head of Corporate Banking, Chicago
                                    
                                    
                    By:    /s/ Dean Balice
                           --------------------------------------------
                    Name:  Dean Balice
                    Title: Senior Vice President, Branch Manager
                                    
                                    
                    THE CIT GROUP/BUSINESS CREDIT, INC. 
                                    
                                    
                    By:    /s/ Nicole Cangelosi
                           --------------------------------------------
                    Name:  Nicole Cangelosi
                    Title: Assistant Secretary
                                    
                                    
                    CITICORP USA, INC.                  
                                    
                                    
                    By:    /s/ Claudia Slacik
                           --------------------------------------------
                    Name:  Claudia Slacik
                    Title: Vice President
                                    
                                    
                    FLEET CAPITAL CORPORATION           
                                    
                                    
                    By:    /s/ Thomas E. Joyce
                           --------------------------------------------
                    Name:  Thomas E. Joyce
                    Title: Senior Vice President
                                    
                                    
                    FLEET NATIONAL BANK                 
                                    
                                    
                    By:    /s/ Kevin J. Chamberlain
                           --------------------------------------------
                    Name:  Kevin J. Chamberlain
                    Title: Vice President

                                       8
<PAGE>
 
                    GOLDMAN SACHS CREDIT PARTNERS L.P.

                    By:    /s/ Thomas R. Hudson, Jr.
                           --------------------------------------------
                    Name:  Thomas R. Hudson, Jr.
                    Title: Authorized Signatory


                    GREEN TREE FINANCIAL SERVICING CORPORATION


                    By:    /s/ Christopher A. Gouskos
                           --------------------------------------------
                    Name:  Christopher A. Gouskos
                    Title: Senior Vice President


                    HELLER FINANCIAL, INC.


                    By:    /s/ Albert J. Forzano
                           --------------------------------------------
                    Name:  Albert J. Forzano
                    Title: Vice President


                    IBJ SCHRODER BUSINESS CREDIT CORP.


                    By:
                           --------------------------------------------
                    Name:
                    Title:


                    JACKSON NATIONAL LIFE INSURANCE COMPANY
                    By:  PPM FINANCE, INC.
                    Its Attorney-in-fact


                    By:
                           --------------------------------------------
                    Name:
                    Title:

                                       9
<PAGE>
 
                    LEHMAN COMMERCIAL PAPER, INC.


                    By:
                           --------------------------------------------
                    Name:
                    Title:


                    NATIONAL CITY COMMERCIAL FINANCE, INC.


                    By:    /s/ Mark Hanak
                           --------------------------------------------
                    Name:  Mark Hanak
                    Title: Assistant Vice President


                    STAR BANK, N.A.


                    By:    /s/ Mike Ehlert
                           --------------------------------------------
                    Name:  Mike Ehlert
                    Title: Vice President

                                       10