<PAGE>

                                                              EXHIBIT 10(i)A(11)

                                OMNIBUS AMENDMENT


         THIS OMNIBUS AMENDMENT (this "AMENDMENT"), dated as of August 31, 2001,
is by and among National Service Industries, Inc., a Delaware corporation
("NSI-DELAWARE"), NSI Enterprises, Inc., a California corporation ("NSI
ENTERPRISES"), National Service Industries, Inc., a Georgia corporation ("NSI
GEORGIA" and, together with NSI-Delaware and NSI Enterprises, the "EXISTING
COMPANIES"), L & C Spinco, Inc., a Delaware corporation ("SPINCO"), The Zep
Group, Inc., a Delaware corporation ("ZEP"), L & C Lighting Group, Inc., a
Delaware corporation ("L & C LIGHTING"), L & C Funding, Inc., a Delaware
corporation formerly known as NSI Funding, Inc. ("SPC" and, together with
Spinco, Zep and L & C Lighting, the "SUCCESSOR COMPANIES"), Blue Ridge Asset
Funding Corporation, a Delaware corporation ("BLUE RIDGE"), and Wachovia Bank,
N.A., individually ("WACHOVIA") and as agent (in such latter capacity, the
"AGENT"), and pertains to (a) that certain Receivables Sale Agreement, dated as
of May 2, 2001, by and between NSI Enterprises and NSI Georgia and collaterally
assigned first, to SPC and then, to the Agent (the "RSA"), (b) that certain
Receivables Sale and Contribution Agreement, dated as of May 2, 2001, by and
between NSI Georgia and SPC (the "RSCA"), (c) that certain Credit and Security
Agreement, dated as of May 2, 2001, by and among SPC, as Borrower, NSI Georgia,
as initial Servicer, Wachovia, as the sole initial Liquidity Bank, Blue Ridge
and the Agent (as heretofore amended, the "CSA"), and (d) that certain
Performance Undertaking dated as of May 2, 2001, by and between NSI-Delaware and
SPC and collaterally assigned to the Agent (the "PERFORMANCE UNDERTAKING" and,
together with the RSA, the RSCA and the CSA, the "SUBJECT AGREEMENTS").
Capitalized terms used and not otherwise defined herein shall have the meanings
attributed to them in the Subject Agreements.

                              W I T N E S S E T H :

                  WHEREAS, on the date hereof, the Existing Companies and
         certain of their affiliates are engaging in a reorganization pursuant
         to an Agreement and Plan of Distribution (the "REORGANIZATION");

                  WHEREAS, immediately following the Reorganization (the
         "EFFECTIVE TIME"), certain of the parties to the Subject Agreements
         will be replaced with certain of the parties hereto, all as more fully
         provided herein; and

                  WHEREAS, some time after the Effective Time, NSI-Delaware will
         distribute ratably to its shareholders, all of Spinco's outstanding
         capital stock (the "DISTRIBUTION");

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

                  1.       NSI-Delaware. Effective from and after the Effective
Time, any and all references in any of the Subject Agreements to NSI-Delaware,
individually or as Performance


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Guarantor, are hereby replaced with NSI-Delaware and Spinco, jointly and
severally. Effective immediately after the Distribution, any and all references
in any of the Subject Agreements to NSI-Delaware and Spinco, jointly and
severally, are hereby replaced with Spinco.

                  2.       NSI Enterprises. Effective from and after the
Effective Time, any and all references in any of the Subject Agreements
(including, without limitation, references in provisions inserted by this
Amendment) to NSI Enterprises are hereby replaced with Zep.

                  3.       NSI Georgia. Effective from and after the Effective
Time, any and all references in any of the Subject Agreements (including,
without limitation, references in provisions inserted by this Amendment) to NSI
Georgia are hereby replaced with L & C Lighting.

                  4.       NSI Funding, Inc. Effective from and after the
Effective Time, any and all references in any of the Subject Agreements to "NSI
Funding, Inc." are hereby replaced with "L & C Funding, Inc."

                  5.       Other Amendments. Effective from and after the
Effective Time:

                           (a)      Exhibit II to each of the RSA and RSCA and
Exhibit III to the CSA are hereby amended and restated in their entirety to read
as set forth in Annex I to this Amendment,

                           (b)      The definition of "RECEIVABLE" in the RSA is
hereby amended and restated in its entirety to read as follows:

                  "RECEIVABLE" means all indebtedness and other obligations owed
         to NSI Enterprises (at the times it arises, and before giving effect to
         any transfer or conveyance under the Agreement), including, without
         limitation, any indebtedness, obligation or interest constituting an
         account, chattel paper, instrument or general intangible, arising in
         connection with the sale of goods or the rendering of services by NSI
         Enterprises and further includes, without limitation, the obligation to
         pay any Finance Charges with respect thereto (except that, for purposes
         of this definition, Receivables generated from NSI Enterprises's "Selig
         Chemical" operations shall not be considered "Receivables" for purposes
         of this definition unless and until (i) the Obligors on the Receivables
         originated by NSI Enterprises's "Selig Chemical" operations are
         instructed to pay all Collections on such Receivables directly to a
         Lock-Box or Collection Account in accordance with Section 8.2(b) of the
         Credit and Security Agreement, and (ii) the Agent has expressly
         consented in writing to such Receivables being considered as
         "Receivables" for purposes of this definition). Indebtedness and other
         rights and obligations arising from any one transaction, including,
         without limitation, indebtedness and other rights and obligations
         represented by an individual invoice, shall constitute a Receivable
         separate from a Receivable consisting of the indebtedness and other
         rights and obligations arising from any other transaction; PROVIDED,
         FURTHER, that any indebtedness, rights or obligations referred to in
         the immediately preceding sentence shall be a Receivable regardless or
         whether the


<PAGE>
         account debtor or NSI Enterprises treats such indebtedness, rights or
         obligations as a separate payment obligation.

                  (c)      The definition of "RECEIVABLE" in the RSCA is hereby
amended and restated in its entirety to read as follows:

                  "RECEIVABLE" means (a) any "Receivable" under and as defined
         in the First-Step Sale Agreement which is conveyed to NSI Georgia in
         accordance with the terms thereof, or (b) all indebtedness and other
         obligations owed to NSI Georgia (at the times it arises, and before
         giving effect to any transfer or conveyance under the Agreement),
         including, without limitation, any indebtedness, obligation or interest
         constituting an account, chattel paper, instrument or general
         intangible, arising in connection with the sale of goods or the
         rendering of services by NSI Georgia's "Lithonia Lighting" division,
         and further includes, without limitation, the obligation to pay any
         Finance Charges with respect thereto. Indebtedness and other rights and
         obligations arising from any one transaction, including, without
         limitation, indebtedness and other rights and obligations represented
         by an individual invoice, shall constitute a Receivable separate from a
         Receivable consisting of the indebtedness and other rights and
         obligations arising from any other transaction; PROVIDED, FURTHER, that
         any indebtedness, rights or obligations referred to in the immediately
         preceding sentence shall be a Receivable regardless or whether the
         Obligor or NSI Georgia treats such indebtedness, rights or obligations
         as a separate payment obligation.

                  6.       Further Assurances. Each of the Existing Companies
and the Successor Companies agrees to execute and deliver to the Agent such UCC
financing statements and amendments thereto or other similar instruments or
documents as may be necessary to perfect the interests in the Receivables,
Related Security and other collateral purported to be conveyed under the RSA,
the RSCA and the CSA and agrees that the Agent may, to the fullest extent
permitted by applicable law, file any such financing statement or amendment
without the signature of such Existing Company or Successor Company, as the case
may be.

                  7.       Notices. All notices and other communications to any
of the Successor Companies or to the SPC provided for under the Subject
Agreements shall be made in writing and shall be addressed to it at the address
set forth beneath its signature to this Amendment..

                  8.       GOVERNING LAW. THIS AMENDMENT SHALL BE CONSTRUED IN
ACCORDANCE WITH THE INTERNAL LAWS (AND NOT THE LAW OF CONFLICTS) OF THE STATE OF
GEORGIA.

                  9.       CONSENT TO JURISDICTION. TO THE FULLEST EXTENT
PERMITTED BY APPLICABLE LAW: (A) EACH OF THE PARTIES HERETO HEREBY IRREVOCABLY
SUBMITS TO THE NON-EXCLUSIVE JURISDICTION OF ANY UNITED STATES FEDERAL OR
GEORGIA STATE COURT SITTING IN FULTON COUNTY, GEORGIA IN ANY ACTION OR
PROCEEDING ARISING OUT OF OR RELATING TO THIS AMENDMENT, THE SUBJECT AGREEMENTS,
OR ANY OTHER DOCUMENT


<PAGE>
EXECUTED IN CONNECTION THEREWITH OR DELIVERED THEREUNDER AND (B) EACH OF THE
PARTIES HERETO HEREBY IRREVOCABLY AGREES THAT ALL CLAIMS IN RESPECT OF SUCH
ACTION OR PROCEEDING MAY BE HEARD AND DETERMINED IN ANY SUCH COURT AND
IRREVOCABLY WAIVES ANY OBJECTION IT MAY NOW OR HEREAFTER HAVE AS TO THE VENUE OF
ANY SUCH SUIT, ACTION OR PROCEEDING BROUGHT IN SUCH A COURT OR THAT SUCH COURT
IS AN INCONVENIENT FORUM.

                  10.      WAIVER OF JURY TRIAL. TO THE MAXIMUM EXTENT PERMITTED
BY APPLICABLE LAW, EACH OF THE PARTIES HERETO HEREBY WAIVES TRIAL BY JURY IN ANY
JUDICIAL PROCEEDING INVOLVING, DIRECTLY OR INDIRECTLY, ANY MATTER (WHETHER
SOUNDING IN TORT, CONTRACT OR OTHERWISE) IN ANY WAY ARISING OUT OF, RELATED TO,
OR CONNECTED WITH THIS AMENDMENT, THE SUBJECT AGREEMENTS OR ANY OTHER DOCUMENT
EXECUTED IN CONNECTION THEREWITH OR DELIVERED THEREUNDER OR THE RELATIONSHIP
ESTABLISHED HEREUNDER OR THEREUNDER

                  11.      Bankruptcy Petition. Each of the Existing Companies
and the Successor Companies hereby covenants and agrees that, prior to the date
that is one year and one day after the payment in full of all outstanding senior
indebtedness owed by Blue Ridge, it will not institute against, or join any
other Person in instituting against, Blue Ridge any bankruptcy, reorganization,
arrangement, insolvency or liquidation proceedings or other similar proceeding
under the laws of the United States or any state of the United States.

                  12.      Miscellaneous. Each of the Subject Agreements, as
modified hereby, is hereby ratified and confirmed by the Successor Companies,
Wachovia, Blue Ridge and the Agent. Unless otherwise specified, references
herein to "SECTION" shall mean a reference to sections of this Amendment.


<PAGE>


                  IN WITNESS WHEREOF, the parties have caused this Amendment to
be duly executed and delivered as of the date first above written.

                                     NATIONAL SERVICE INDUSTRIES, INC., A
                                     DELAWARE CORPORATION

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


                                     NSI ENTERPRISES, INC., A CALIFORNIA
                                     CORPORATION


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


                                     NATIONAL SERVICE INDUSTRIES, INC., A
                                     GEORGIA CORPORATION



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



<PAGE>


                                     L & C SPINCO, INC., A DELAWARE CORPORATION



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

                                     ADDRESS FOR NOTICES:

                                     NSI Center
                                     1420 Peachtree Street, N.E.
                                     Atlanta, Georgia 30309
                                     Attention: Treasurer
                                     Telecopier: 404-853-1330
                                     Telephone: 404-853-1368



                                     THE ZEP GROUP, INC., A DELAWARE CORPORATION

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

                                     ADDRESS FOR NOTICES:

                                     NSI Center
                                     1420 Peachtree Street, N.E.
                                     Atlanta, Georgia 30309
                                     Attention: Treasurer
                                     Telecopier: 404-853-1330
                                     Telephone: 404-853-1368


<PAGE>




                                     L & C LIGHTING GROUP, INC., A DELAWARE
                                     CORPORATION

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

                                     ADDRESS FOR NOTICES:

                                     NSI Center
                                     1420 Peachtree Street, N.E.
                                     Atlanta, Georgia 30309
                                     Attention: Treasurer
                                     Telecopier: 404-853-1330
                                     Telephone: 404-853-1368



                                     L & C FUNDING, INC., A DELAWARE
                                     CORPORATION FORMERLY KNOWN AS NSI FUNDING,
                                     INC.


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

                                     ADDRESS FOR NOTICES:

                                     NSI Center
                                     1420 Peachtree Street, N.E.
                                     Atlanta, Georgia 30309
                                     Attention: Treasurer
                                     Telecopier: 404-853-1330
                                     Telephone: 404-853-1368


<PAGE>




                                     WACHOVIA BANK, N.A., INDIVIDUALLY AND AS
                                     AGENT


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

                                     BLUE RIDGE ASSET FUNDING CORPORATION

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

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


<PAGE>


                                                    ANNEX I TO OMNIBUS AMENDMENT

                                EXHIBIT II TO RSA

   Chief Executive Office; Principal Place of Business; Locations of Records;
               Federal Employer Identification Number; Other Names


CHIEF EXECUTIVE OFFICE:
         1420 Peachtree Street
         Atlanta, Georgia  30309

PRINCIPAL PLACE OF BUSINESS:
         1420 Peachtree Street
         Atlanta, Georgia  30309

LOCATIONS OF RECORDS:

         1420 Peachtree Street
         Atlanta, Georgia  30309

         Highway 41 North
         Emerson, Georgia  30137

         1310 Seaboard Industrial Blvd.
         Atlanta, Georgia  30318

FEDERAL EMPLOYER IDENTIFICATION NUMBER:     58-2633373

LEGAL, TRADE AND ASSUMED NAMES:             Enforcer Products
                                            National Chemical
                                            Zep Aviation
                                            Zep Manufacturing Company, Armor All
                                            Products division
                                            Selig Chemical Industries
                                            Selig Industries
                                            Zep Manufacturing Company
                                            Zep Manufacturing Company of Canada



<PAGE>
                               EXHIBIT II TO RSCA

                   Places of Business; Locations of Records;
             Federal Employer Identification Number(s); Other Names



PLACES OF BUSINESS:

         1420 Peachtree Street
         Atlanta, Georgia  30309



LOCATIONS OF RECORDS:

         1420 Peachtree Street
         Atlanta, Georgia  30309

         One Lithonia Way
         Conyers, Georgia  30012


FEDERAL EMPLOYER IDENTIFICATION NUMBER:     58-2633371


LEGAL, TRADE AND ASSUMED NAMES:
                                                     Lithonia Lighting
                                                     Major Reflector
                                                     Holophane
                                                     Metal Optics
                                                     Austin Lighting Products
                                                     Antique Street Lamps
                                                     Peerless Lighting
                                                     Hydrel



<PAGE>


                               EXHIBIT III TO CSA
          PLACES OF BUSINESS OF THE LOAN PARTIES; LOCATIONS OF RECORDS;

                    FEDERAL EMPLOYER IDENTIFICATION NUMBER(S)



PLACES OF BUSINESS:

         1420 Peachtree Street
         Atlanta, Georgia  30309



LOCATIONS OF RECORDS:

         1420 Peachtree Street
         Atlanta, Georgia  30309

         One Lithonia Way
         Conyers, Georgia  30012

         Highway 41 North
         Emerson, Georgia  30137

         1310 Seaboard Industrial Blvd.
         Atlanta, Georgia  30318



FEDERAL EMPLOYER IDENTIFICATION NUMBER:

         L&C Lighting:     58-2633371
         The Zep Group:    58-2633373
         Borrower:         58-2616706

PRIOR BORROWER LEGAL NAMES, BORROWER TRADE AND ASSUMED NAMES:  None


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