Document:

<PAGE>   1
                                                                    EXHIBIT 10.1

                       THIRD AMENDMENT TO CREDIT AGREEMENT

                  AMENDMENT AND WAIVER TO CREDIT AGREEMENT (this "Amendment"),
dated as of May 10, 2000, among Generac Portable Products, Inc., a Delaware
corporation ("Holdings"), GPPW, Inc., a Wisconsin corporation ("WisCorp" and
together with Holdings, the "Parent Guarantors"), Generac Portable Products,
LLC, a Delaware limited liability company (the "Borrower"), the Banks party
thereto from time to time, and Bankers Trust Company, as Administrative Agent.
Unless otherwise defined herein, all capitalized terms used herein shall have
the respective meanings provided such terms in the Credit Agreement referred to
below.

                              W I T N E S S E T H:

                  WHEREAS, the Borrowers, the Banks, the Administrative Agent
and the Parent Guarantors are parties to a Credit Agreement, dated as of July 9,
1998 (as amended, modified or supplemented to the date hereof, the "Credit
Agreement"); and

                  WHEREAS, the parties hereto wish to amend the Credit Agreement
as herein provided;

                  NOW, THEREFORE, it is agreed:

         I.       AMENDMENTS TO THE CREDIT AGREEMENT

                  A. Section 9.07(a) of the Credit Agreement is hereby amended
by deleting clause (iii) therein and inserting in lieu thereof the following new
clause (iii):

                     "(iii) $5 million during the calendar year ending on
December 31, 2000;"

                   B. Section 9.08 of the Credit Agreement is hereby amended by
deleting the table appearing therein and inserting in lieu thereof the following
table:

<TABLE>
<CAPTION>
                   Fiscal Quarter Ended Closest to      Ratio
                   -------------------------------      -----
                   <S>                                <C>
                   June 30, 2000                      1.70:1.00
                   September 30, 2000                 1.65:1.00
                   December 31, 2000                  1.60:1.00
                   March 31, 2001                     1.90:1.00
                   June 30, 2001                      2.20:1.00
                   September 30, 2001                 2.45:1.00
                   December 31, 2001                  2.55:1.00
                   March 31, 2002                     2.65:1.00
                   June 30, 2002                      2.75:1.00
                   September 30, 2002                 2.85:1.00
                   December 31, 2002 and thereafter   3.00:1.00
</TABLE>
<PAGE>   2

                   C. Section 9.09 of the Credit Agreement is hereby amended by
deleting the table appearing therein and inserting in lieu thereof the following
table:

<TABLE>
<CAPTION>
                   Fiscal Quarter Ended Closest To      Ratio
                   -------------------------------      -----
                   <S>                                <C>
                   June 30, 2000                      5.60:1.00
                   September 30, 2000                 5.70:1.00
                   December 31, 2000                  5.60:1.00
                   March 31, 2001                     5.20:1.00
                   June 30, 2001                      4.75:1.00
                   September 30, 2001                 4.50:1.00
                   December 31, 2001                  4.20:1.00
                   March 31, 2002                     4.10:1.00
                   June 30, 2002                      4.10:1.00
                   September 30, 2002                 3.90:1.00
                   December 31, 2002 and thereafter   3.75:1.00
</TABLE>

                   D. Section 9.10 of the Credit Agreement is hereby amended by
deleting the table appearing therein and inserting in lieu thereof the following
table:

<TABLE>
<CAPTION>
                   Fiscal Quarter Ended Closest To    Minimum EBITDA
                   -------------------------------    --------------
                   <S>                                <C>
                   June 30, 2000                      $36 million
                   September 30, 2000                 $35 million
                   December 31, 2000                  $34 million
                   March 31, 2001                     $38 million
                   June 30, 2001                      $44 million
                   September 30, 2001                 $49 million
                   December 31, 2001                  $52 million
                   March 31, 2002                     $53 million
                   June 30, 2002                      $54 million
                   September 30, 2002                 $55 million
                   December 31, 2002                  $56 million
                   March 31, 2003                     $57 million
                   June 30, 2003                      $58 million
                   September 30, 2003                 $60 million
                   December 31, 2003 and thereafter   $62 million
</TABLE>

                   E. The definition of "Applicable Commitment Commission
Percentage" and "Applicable Margin" in Section 11 of the Credit Agreement is
hereby amended by deleting the table appearing therein and inserting in lieu
thereof the following table:

                                      -2-
<PAGE>   3

<TABLE>
<CAPTION>
                                    APPLICABLE      A TERM LOANS AND      A TERM LOANS AND
                                    COMMITMENT       REVOLVING LOANS       REVOLVING LOANS      B TERM LOANS        B TERM LOANS
                                    COMMISSION        MAINTAINED AS         MAINTAINED AS       MAINTAINED AS       MAINTAINED AS
      LEVEL      LEVERAGE RATIO     PERCENTAGE       BASE RATE LOANS      EURODOLLAR LOANS     BASE RATE LOANS    EURODOLLAR LOANS
      ------     --------------    -----------       ---------------      -----------------    ---------------    ----------------
<S>             <C>                <C>             <C>                   <C>                  <C>                <C>
      1         Greater than or        0.50%             1.75%                 2.75%                2.25%              3.25%
                equal to
                5.0:1.00
      2         Greater than or        0.50%             1.50%                 2.50%                2.00%              3.00%
                equal to 4.50
                but less than
                5.0:1.00
      3         Greater than or
                equal to 4.25:1        0.50%             1.25%                 2.25%                1.75%              2.75%
                but less than
                4.50:1
      4         Greater than or
                equal to 3.75:l        0.375%            1.00%                 2.00%                1.50%              2.50%
                but less than
                4.25:1
      5         Greater than or
                equal to 3.25:1        0.375%            0.75%                 1.75%                1.25%              2.25%
                but less than
                3.75:1
      6         Greater than or
                equal to 2.75:1        0.30%             0.50%                 1.50%                1.00%              2.00%
                but less than
                3.25:1
      7         Less than 2.75:1       0.25%             0.125%                1.125%               0.75%              1.75%
</TABLE>

         II.       AMENDMENT FEE

                   A. The Borrower hereby covenants and agrees that, it should
pay each Bank which executes and delivers to the Administrative Agent a
counterpart hereof by 5:00 P.M. (New York time) on Wednesday, May 10, 2000, a
cash fee in an amount equal to 25 basis points (0.25%) of an amount equal to the
sum of the outstanding Term Loans of such Bank and the Revolving Loan Commitment
of such consenting Bank, in each case as in effect on the Amendment Effective
Date (as hereinafter defined). All fees pursuant to this clause A are due and
payable on the Amendment Effective Date and shall be paid by the Borrower to the
Administrative Agent for distribution to the Banks.

         III.      MISCELLANEOUS PROVISIONS

                   A. In order to induce the Banks to enter into this Amendment,
each of the Borrowers hereby represents and warrants that:

                                      -3-
<PAGE>   4

                      1. no Default or Event of Default exists as of the
         Amendment Effective Date, both before and after giving effect to this
         Amendment; and

                      2. all of the representations and warranties contained in
         the Credit Agreement and the other Credit Documents are true and
         correct in all material respects as of the Amendment Effective Date,
         both before and after giving effect to this Amendment, with the same
         effect as though such representations and warranties had been made on
         and as of the Amendment Effective Date (it being understood that any
         representation or warranty made as of a specific date shall be true and
         correct in all material respects as of such specific date).

                   B. This Amendment is limited as specified and shall not
constitute a modification, acceptance or waiver of any other provision of the
Credit Agreement or any other Credit Document.

                   C. This Amendment may be executed in any number of
counterparts and by the different parties hereto on separate counterparts, each
of which counterparts when executed and delivered shall be an original, but all
of which shall together constitute one and the same instrument. A complete set
of counterparts shall be lodged with the Borrower and the Administrative Agent.

                   D. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAWS
OF THE STATE OF NEW YORK.

                   E. This Amendment shall become effective on the date (the
"Amendment Effective Date") when the Borrower, each of the Parent Guarantors,
the Administrative Agent and the Required Banks shall have signed a counterpart
hereof (whatever the same or different counterparts) and shall have delivered
(including by way of facsimile transmission) the same to the Administrative
Agent at its Notice Office and the Amendment Fees set forth in Section II shall
have been paid.

                   F. From and after the Amendment Effective Date, all
references in the Credit Agreement and each of the other Credit Documents to the
Credit Agreement shall be deemed to be references to the Credit Agreement as
modified hereby.

                                      * * *

                                      -4-
<PAGE>   5

                   IN WITNESS WHEREOF, the parties hereto have caused their duly
authorized officers to execute and deliver this Amendment as of the date first
above written.

                                  GENERAC PORTABLE PRODUCTS, LLC

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

                                  GENERAC PORTABLE PRODUCTS, INC

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

                                  GPPW, INC.

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

                                  BANKERS TRUST COMPANY, Individually and as
                                      Administrative Agent

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

<PAGE>   6

                                  BANK OF AMERICA NATIONAL TRUST AND SAVINGS
                                  ASSOCIATION

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

<PAGE>   7

                                  LASALLE BANK NATIONAL ASSOCIATION

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

<PAGE>   8

                                  UNION BANK OF CALIFORNIA, N.A.

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

<PAGE>   9

                                  BANK ONE, N. A.

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

<PAGE>   10

                                  THE FUJI BANK, LIMITED

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

<PAGE>   11

                                  MOUNTAIN CAPITAL CLO 1, LTD.

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

<PAGE>   12

                                  FLEET BUSINESS CREDIT CORPORATION

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

<PAGE>   13

                                  HARCH CLO I LIMITED

                                  By:
                                     -------------------------------------------
                                      Name:
                                      Title:<PAGE>   1
                                                                 EXHIBIT 4.1
                                                                            ----

                                                                   EXECUTED COPY

================================================================================

                             SUPPLEMENTAL INDENTURE

                                      NO. 1

                                       TO

                       INDENTURE DATED AS OF MAY 15, 1999

================================================================================

<PAGE>   2

          This SUPPLEMENTAL INDENTURE NO. 1 to INDENTURE (this "Supplemental
Indenture") is entered into among Lear Corporation, a Delaware corporation (the
"Company"), Lear Operations Corporation, a Delaware corporation ("LOC"), Lear
Corporation Automotive Holdings, a Delaware corporation ("LCAH"), Lear Seatings
Holdings Corp. # 50, a Delaware corporation ("Lear # 50"), Lear Corporation EEDS
and Interiors, a Delaware corporation ("Lear Interiors"), and The Bank of New
York, a New York banking corporation, as Trustee (the "Trustee").

                                    RECITALS

          WHEREAS, the Company, LOC, LCAH and the Trustee have entered into that
certain Indenture dated as of May 15, 1999 (the "Indenture") providing for the
issuance and delivery by the Company of its 7.96% Senior Notes due 2005 (the
"7.96% Notes") and its 8.11% Senior Notes due 2009 (the "8.11% Notes" and,
together, with the 7.96% Notes, the "Notes");

          WHEREAS, Lear # 50, a subsidiary of the Company, will become,
concurrently with the execution and delivery of this Supplemental Indenture, a
guarantor under the Principal Credit Facilities;

          WHEREAS, Lear Interiors, a subsidiary of the Company, will become,
concurrently with the execution and delivery of this Supplemental Indenture, a
guarantor under the Principal Credit Facilities; and

          WHEREAS, pursuant to Section 10.06 of the Indenture, any subsidiary of
the Company that becomes a guarantor under the Principal Credit Facilities is
required to become a Guarantor under the Indenture;

          NOW, THEREFORE, in consideration of the mutual agreements contained
herein and for other good and valuable consideration, the receipt and adequacy
of which are hereby acknowledged, the parties hereto agree as follows for the
benefit of each other party and for the equal and ratable benefit of the Holders
of the Notes:

                                      -2-
<PAGE>   3

          Section 1.  GUARANTEE.

          For value received, each of Lear # 50 and Lear Interiors hereby agrees
to become a party to the Indenture as a Guarantor under and pursuant to Article
10 of the Indenture and to jointly and severally unconditionally guarantee to
each Holder and the Trustee (a) the due and punctual payment in full of
principal of and interest on the Notes when due, whether at stated maturity,
upon acceleration, redemption or otherwise, (b) the due and punctual payment in
full of interest on the overdue principal of and, to the extent permitted by
law, interest on the Notes, and (c) the due and punctual payment of all other
Obligations of the Company and the other Guarantors to the Holders and the
Trustee under the Indenture and the Notes, including, without limitation, the
payment of fees, expenses, indemnification or other amounts.

          Section 2. MISCELLANEOUS.

          2.1. GOVERNING LAW. THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY
AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

          2.2. Confirmation of the Indenture. Except as amended hereby, the
Indenture shall remain in full force and effect and is hereby ratified and
confirmed in all respects.

          2.3. Multiple Counterparts. The parties may sign multiple counterparts
of this Supplemental Indenture. Each signed counterpart shall be deemed an
original, but all of them together represent one and the same agreement.

          2.4. Separability. Each provision of this Supplemental Indenture shall
be considered separable and if for any reason any provision which is not
essential to the effectuation of the basic purpose of this Supplemental
Indenture shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

          2.5. Headings. The captions of the various section headings of this
Supplemental Indenture have been inserted for convenience of reference only, are
not to be considered a part hereof, and shall in no way modify or restrict any
of the terms or provisions hereof.

          2.6. The Trustee. The Trustee shall not be responsible in any manner
whatsoever for or in respect of the validity or sufficiency of this Supplemental
Indenture or for or in respect of the recitals contained herein, all of which
recitals are made solely by the Company and the Guarantors.

          2.7. Definitions. All terms defined in the Indenture shall have the
same meaning in this Supplemental Indenture unless otherwise defined herein.

                            [signature page follows]

<PAGE>   4

          IN WITNESS WHEREOF, the parties hereto caused this Supplemental
Indenture to be duly executed as of this 2nd day of May, 2000.

                      LEAR CORPORATION

                      By: /s/ Joseph F. McCarthy
                          ------------------------------------------------------
                          Name: Joseph F. McCarthy
                          Title:  Vice President, Secretary and General Counsel

                      LEAR OPERATIONS CORPORATION

                      By: /s/ Joseph F. McCarthy
                          ------------------------------------------------------
                          Name: Joseph F. McCarthy
                          Title:  Vice President, Secretary and General Counsel

                      LEAR CORPORATION AUTOMOTIVE HOLDINGS

                      By: /s/ Joseph F. McCarthy
                          ------------------------------------------------------
                          Name: Joseph F. McCarthy
                          Title: Vice President and Secretary

                      LEAR SEATINGS HOLDINGS CORP. # 50

                      By: /s/ Joseph F. McCarthy
                          ------------------------------------------------------
                          Name: Joseph F. McCarthy
                          Title: Secretary and General Counsel

                      LEAR CORPORATION EEDS AND INTERIORS

                      By: /s/ Joseph F. McCarthy
                          ------------------------------------------------------
                          Name: Joseph F. McCarthy
                          Title: Vice President and Secretary

                      THE BANK OF NEW YORK, as Trustee

                      By: /s/ Terence Rawlins
                          ------------------------------------------------------
                          Name:  Terence Rawlins
                          Title: Assistant Vice President

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00013-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00013-of-00352.parquet"}]]