Document:

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                                                                EXHIBIT 10.43

[LOGO]
BURKE INDUSTRIES

February 4, 2000

Theodore M. Clark
177 Oak Meadow Road
Sierra Madre, CA 91024

Dear Ted:

This will confirm certain amendments to your Employment Agreement (the
"Agreement"), which was made and entered into as of September 16, 1999. The
purpose of these amendments, which it is agreed shall be effective
retroactively as of November 1, 1999, is to reflect the accelerated pace of
the transition pursuant to which you became President of Burke. Any
capitalized term used herein shall have the meaning assigned to such term in
the Agreement.

In Section 1 of the Agreement, the date "November 1, 1999" shall be
substituted for the date "January 1, 2000" and the date "October 31, 2001"
shall be substituted for the date "December 31, 2000."

In Section 2 of the Agreement, the first sentence shall be deleted and the
following substituted therefor: "Clark shall be employed as the President of
Burke effective as of November 1, 1999, and, in addition, shall assume the
duties of Chief Executive Officer of Burke effective February 1, 2000."

In Section 4 of the Agreement, the date "November 1, 1999" shall be
substituted for the date "January 1, 2000."

In Section 10.C. of the Agreement, the date "October 31, 2001" shall be
substituted for the date "December 31, 2001."

Please acknowledge your acceptance of these amendments by signing both copies
of this letter where indicated below, and returning one signed copy to me.
The duplicate signed copy should be retained for your records.

Your truly,                                 Accepted and Agreed:

/s/ George A. Sawyer                        /s/ Theodore M. Clark
----------------------------------          ------------------------------
George A. Sawyer                            Theodore M. Clark
Chairman of the Board

13767 Freeway Drive, Santa Fe Springs, California 90670 - (562) 926-6556
(800) 221-0923 Fax: (562) 926-3710<PAGE>

                                                             EXHIBIT 10.44

     EXTENSION AND FIRST AMENDMENT OF LEASE, dated as of January 13, 1994,
by and between RTC PROPERTIES, INC., a New York corporation having an office
at 1185 Avenue of the Americas, Suite 310, New York, New York 10036 ("Lessor")
and MERCER PRODUCTS CO., INC., a New York corporation having an office at
Hackensack Avenue, Building 10, Kearny, New Jersey 07032 ("Lessee").

                              WITNESSETH:

     WHEREAS, Lessor, as lessor, and Lessee, as lessee, entered into a
lease agreement dated as of December 1, 1988 (hereinafter referred to as the
"Lease Agreement"), covering premises including a portion of Building 10 at
the River Terminal Facility, Kearny, New Jersey, as more particularly
described therein (the "Premises"), and

     WHEREAS, the Lease Agreement will expire on April 30, 1994; and

     WHEREAS, Lessor and Lessee desire to extend the Lease Agreement for
an additional term of one year and, coincident with such extension, to
amend certain other provisions of the Lease Agreement;

     NOW, THEREFORE, Lessor and Lessee do hereby agree to the extension of
theLease Agreement and to the amendment of the Lease Agreement as follows:

          PARAGRAPH 1. Section 1.01 of the Lease Agreement is hereby
     amended by deleting the expiration date "April 30, 1994" and inserting
     in its place and stead the date "April 30, 1995".

          PARAGRAPH 2. During the one year extension, the Fixed Rent
     payable by Lessee pursuant to Section 2.01 shall remain unchanged.

          PARAGRAPH 3. Article THIRTY-FOURTH is hereby amended to provide
     that the term "Expiration Date originally provided for herein" shall
     refer to the Term as extended herein, i.e., April 30, 1995.

          PARAGRAPH 4. Unless otherwise provided expressly herein,
     initially capitalized terms used herein shall have the same meanings
     that they have in the Lease Agreement.

          PARAGRAPH 5. Except as modified herein, the provisions of the
     Lease Agreement shall continue in full force and effect.

     IN WITNESS WHEREOF, Lessor and Lessee have duly executed this Extension
and First Amendment of Lease as of the day and year first above written.

                                           RTC PROPERTIES, INC.

                                       By:
                                           -------------------------------
                                           MERCER PRODUCTS CO., INC.

                                       By: /s/ Thomas S. Keup
                                           -------------------------------
                                           Thomas S. Keup

ATTEST:

By: /s/ Phyllis P. Bartle
    -----------------------------
    Phyllis P. Bartle
    [NOTARY SEAL]<PAGE>

                                                            EXHIBIT 10.45

     EXTENSION AND SECOND AMENDMENT OF LEASE, dated as of January 23, 1995,
by and between RTC PROPERTIES, INC., a New York corporation having an
office at 1185 Avenue of the Americas, Suite 310, New York, New York 10036
("Lessor") and MERCER PRODUCTS CO., INC., a New York corporation having an
office at Hackensack Avenue, Building 10, Kearny, New Jersey 07032
("Lessee").

                             WITNESSETH:

     WHEREAS, Lessor, as lessor, and Lessee, as lessee, entered into a
lease agreement dated as of December 1, 1988 as amended by an Extension and
First Amendment of Lease dated as of January 13, 1994 (hereinafter referred to
as the "Lease Agreement"), covering premises including a portion of Building
10 at the River Terminal Facility, Kearny, New Jersey, as more particularly
described therein (the "Premises"); and

     WHEREAS, the Lease Agreement will expire on April 30, 1995; and

     WHEREAS, Lessor and Lessee desire to extend the Lease Agreement for
an additional term of two years and, coincident with such extension, to
amend certain other provisions of the Lease Agreement;

     NOW, THEREFORE, Lessor and Lessee do hereby agree to the extension of
the Lease Agreement and to the amendment of the Lease Agreement as follows:

          PARAGRAPH 1. Section 1.01 of the Lease Agreement is hereby
     amended by deleting the expiration date "April 30, 1995" and inserting
     in its place and stead the date "April 30, 1997".

          PARAGRAPH 2. During the two year extension, the Fixed Rent
     payable by Lessee pursuant to Section 2.01 shall remain unchanged.

          PARAGRAPH 3. Article THIRTY-FOURTH is hereby amended to provide
     that the term "Expiration Date originally provided for herein" shall
     refer to the Term as extended herein, i.e., April 30, 1997.

          PARAGRAPH 4. Unless otherwise provided expressly herein,
     initially capitalized terms used herein shall have the same meanings
     that they have in the Lease Agreement.

          PARAGRAPH 5. Except as modified herein, the provisions of the
     Lease Agreement shall continue in full force and effect.

     IN WITNESS WHEREOF, Lessor and Lessee have duly executed this Extension
and Second Amendment of Lease as of the day and year first above written.

                                           RTC PROPERTIES, INC.

                                       By: /s/ John Neu
                                           --------------------------------
                                           John Neu

                                           MERCER PRODUCTS CO., INC.

                                       By: /s/ Thomas S. Keup
                                           --------------------------------
                                           Thomas S. Keup

ATTEST:

By: /s/ Phyllis Bartle
    ----------------------------
    Phyllis Bartle<PAGE>

                                                           EXHIBIT 10.46

         THIRD AMENDMENT AND EXTENSION OF AGREEMENT OF LEASE

     THIS THIRD AMENDMENT AND EXTENSION OF AGREEMENT OF LEASE, dated as
of March 26, 1997, by and between RTC PROPERTIES, INC., A NEW YORK
CORPORATION, with offices at 100 Central Avenue, South Kearny, New Jersey
07032, (herein called "Lessor"), and MERCER PRODUCTS CO., INC., A NEW YORK
CORPORATION, with offices at Building 10, Hackensack Avenue, South Kearny, New
Jersey 07032, (herein called "Lessee").

                            WITNESSETH:

     WHEREAS, Lessor and Lessee entered into an Agreement of Lease dated as
of December 1, 1988, covering premises known as Building 10, Hackensack
Avenue, South Kearny, New Jersey, also known as Lot 20 in Block 294 on the
current Tax Map of the Town of Kearny. The land and building are a part of an
industrial park (the "Facility"), known and designated as Lots 20, 12, 13 and
14 in Block 294 on the said current Tax Map;

     WHEREAS, Lessor and Lessee entered into an Extension and First Amendment
of Lease dated as of January 13, 1994, extending the term "Expiration Date"
from April 30, 1994 to April 30, 1995;

     WHEREAS, Lessor and Lessee entered into an Extension and Second
Amendment of Agreement of Lease dated as of January 23, 1995, extending the
"Expiration Date" from April 30, 1995 to April 30, 1997;

     WHEREAS, Lessor and Lessee desire to extend the term of the Lease for
three (3) years, from April 30, 1997 to April 30, 2000;

<PAGE>

     WHEREAS, Lessor and Lessee further desire to add 10,000 square feet
of contiguous space to the Premises covered by the said Agreement of Lease
and First and Second Amendments of Agreement of Lease;

     WHEREAS, Lessor and Lessee have agreed to other terms and conditions as
set forth herein;

     WHEREAS, Lessor and Lessee desire to let said Agreement of Lease dated
as of December 1, 1988, said Extension and First Amendment of Agreement of
Lease dated as of January 13, 1994, and Extension and Second Amendment of
Agreement of Lease dated as of January 23, 1995, remain in full force and
effect as to all terms and conditions contained therein and to the original
Premises known as Building 10B and the additional 10,000 square feet of
contiguous space;

     NOW, THEREFORE, Lessor and Lessee do hereby extend and amend the
Agreement of Lease as follows:

     1. PREMISES. Lessor is the owner of the land and building which is part
of an industrial park known and designated as Lots 12 and 20 in Block 294 on
the Tax Map of the leases to Lessee and Lessee leases from Lessor for the
term, at the rental and upon all of the conditions set forth in said
Agreement of Lease dated as of December 1, 1988, Extension and First
Amendment of Agreement Lease dated as of January 13, 1994, and Extension and
Second Amendment of Agreement of Lease dated as of January 23, 1995, and as
set forth in this said Third Amendment and Extension of Agreement of Lease, a
portion of the land and the Building known as 10B (15,000

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square feet) and an additional 10,000 square feet of contiguous space, for a
total of 25,000 square feet, together with the building equipment attached or
appurtenant thereto, located thereon and used solely in connection with the
operation and maintenance thereof.

     2. ARTICLE FIRST -- DEMISE AND TERM OF DEMISE. The term of this Third
Amendment and Extension of Agreement of Lease for the premises (Building 10B
-15,000 square feet and 10,000 square feet of contiguous space, for a total
of 25,000 square feet) shall commence on a date sixty (60) days from the date
of the execution of this Third Amendment and Extension of Agreement of Lease,
andexpire on April 30, 2000, unless sooner terminated pursuant to the
provisions of the above-mentioned said Agreements.

     3. ARTICLE SECOND -- RENT. Lessee shall pay to Lessor rent for the
promises (Building 10B -- 15,000 square feet and 10,000 square feet
of contiguous space for a total of 25,000 square feet), during the term, over
and above the other and additional payments to be made by Lessee, as
hereinafter provided, or as provided in the Agreement of Lease dated as of
December 1, 1988 or the Extensions and Amendments of Agreements of Lease
mentioned above, and without any offset or deduction, of ONE HUNDRED
FIFTY-FOUR THOUSAND DOLLARS ($154,000.00) per annum, NET (based upon a rate of
$6.16 per square foot per annum NET), payable on the first day of each and
every month during the term. Rent for any period during the term hereof which
is for less than

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one (1) month shall be a pro rata portion of the monthly installment.
Rent shall be payable in lawful money of the United States to Lessor at
the address stated herein or to such other persons or at such other
places as Lessor may designate in writing.

     4. ARTICLE THIRD -- TAXES AND ESCALATION RENT. In accordance with the
provisions of Article Third of the Agreement of Lease dated as of December
1, 1988, Lessee shall, as additional rent, pay all charges set forth
thereunder subject to a calculation as set forth in Article Third, but
substituting the square footage of Building 10B -- 15,000 square feet and
10,000 additional continuous square feet, for a total of 25,000 square feet,
for the square footage set forth in said original Agreement of Lease. In
addition, the Proportional Land Impositions shall likewise be adjusted
substituting as numerator the number of square feet of land under the
Premises (Building 10B and the additional 10,000 contiguous square feet) and
the number of square feet of land constituting the parking lot, and the
denominator being the total number of square feet of land comprising the
Land. All other terms and conditions of Article Third shall remain in full
force and effect.

     5. ARTICLE FOURTH -- USE OF PREMISES. Lessee shall have the right to
use the Premises (Building 10B and the additional 10,000 contiguous square
feet) for warehousing, distribution and office use incidental thereto, and
for no other purpose, as set forth in Article Fourth of the Agreement of
Lease mentioned

                                       4

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above.

     6. ARTICLE THIRTY-SECOND -- SECURITY DEPOSIT. Lessee has deposited with
Lessor a sum pursuant to said Agreement of Lease dated as of December 1,
1988. Said sum shall remain deposited with regard to this Third Amendment and
Extension of Lease. All other terms and conditions of Article Thirty-Second
of said Agreement of Lease shall remain in full force and effect.

     7. ARTICLE THIRTY-FOURTH -- RENEWAL TERM. Lessor and Lessee agree
that there shall be no further right to extend the term of this Lease beyond
the date set forth herein, namely April 30, 2000.

     8. WORK LETTER. Lessor agrees at Lessor's expense to do the
following work at said Premises:

          (a) construct a new demising wall between Units 10C and 10B;

          (b) create an 8' x 10' opening in the said demising wall.

     9. Except as set forth herein, and as amended and extended by this Third
Amendment and Extension of Agreement of Lease, the terms and conditions of
the Agreement of Lease dated as of December 1, 1988, the Extension and First
Amendment of Agreement of Lease dated as of January 13, 1994, and the
Extension and Second Amendment of Agreement of Lease dated as of January 23,
1995, shall continue in full force and effect.

     IN WITNESS WHEREOF, Lessor and Lessee have duly executed this
Third Amendment and Extension of Lease as of the day and

                                       5

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year first above written.

                                           RTC PROPERTIES, INC.

                                       By:
                                           --------------------------

WITNESS:

-------------------------

                                           MERCER PRODUCTS CO., INC.

                                       By: /s/ J.J. Kaziow
                                           ---------------------------
                                           J.J. Kaziow
                                           PRESIDENT
WITNESS:
/s/ [ILLEGIBLE]
---------------------------

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