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                                                                     Exhibit 4.1

                        AMENDMENT OF GUARANTEE AGREEMENT

         GUARANTEE, dated as of March 15, 2003, made by Foster Wheeler Ltd., a
company incorporated under the laws of Bermuda (the "Guarantor") in favor of the
FW Preferred Capital Trust I, a business trust organized under the laws of
Delaware (the "Trust"). Capitalized terms used herein and not otherwise defined
shall have the meaning ascribed to such terms in the Company Guarantee (defined
below).

                                W I T E S S E T H

         WHEREAS, pursuant to a declaration of trust, dated as of May 8, 1998,
executed by Foster Wheeler LLC (as successor to Foster Wheeler Corporation by
operation of merger), a limited liability company organized under the laws of
Delaware, (the "Company") and the trustees of the Trust, the Trust has issued
9.00% Preferred Securities, Series I (liquidation amount $25 per preferred
security) (the "Trust Preferred Securities");

         WHEREAS, in connection with the issuance by the Trust of the Trust
Preferred Securities, the Company provided a guarantee pursuant to a Guarantee
Agreement (the "Company Guarantee"), dated as of January 13, 1999, between the
Company and the Guarantee Trustee for the benefit of the Holders from time to
time of the Trust Preferred Securities (the "Holders") of the Guarantee Payments
under the terms and conditions set forth in the Company Guarantee;

         WHEREAS, Section 9.2 of the Company Guarantee provides that the Company
Guarantee may be amended in a manner that does not materially adversely affect
the Holders without the consent of the Holders;

         WHEREAS, the Company and the Guarantor desire that the Guarantor shall
fully and unconditionally, guarantee the Guarantee Payments; and

         WHEREAS, the Company and the Guarantor desire that their obligations
shall be joint and several.

         NOW, THEREFORE, in consideration of the foregoing and other benefits
accruing to the Guarantor, the receipt and sufficiency of which are hereby
acknowledged, the Guarantor hereby makes the following representations and
warranties to the Trust and hereby covenants and agrees with the Trust as
follows:

         1. Guarantee. The Guarantor fully and unconditionally, and jointly and
severally with the Company, guarantees the Guarantee Payments.

         2. Subordination. This Guarantee shall be subordinated and junior in
right of payment to all indebtedness of the Guarantor, whether such indebtedness
is outstanding on the date hereof or thereafter incurred, to the same extent and
in the same manner as the Company's obligations on the Company Guarantee are
subordinated pursuant to the terms of Section 6.1 of the Guarantee Agreement.

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         3. Binding Effect. This Guarantee shall be binding upon the Guarantor
and its successors and assigns and shall inure to the benefit of the Trust and
its successors and assigns.

         4. Amendment; Discharge. Neither this Guarantee nor any provision
hereof may be changed, waived, discharged or terminated orally, but only by an
instrument in writing signed by the parties hereto.

         5. Notices. All notices provided hereunder shall be deemed made when
delivered to the principal executive offices of the party to be notified.

         6. Governing Law. This Guarantee shall be governed by and construed in
accordance with the internal laws of the State of New York applicable to
agreements made and to be performed entirely within such State, without regard
to the conflicts of law principles of such State.

         7. Trustee. The Trustee makes no representations as to the validity or
sufficiency of this Guarantee. The statements and recitals herein are deemed to
be those of the Company and the Guarantor and not of the Trustee.

                                      -2-
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         IN WITNESS WHEREOF, the Guarantor had caused this Guarantee to be
executed and delivered as of the date first written above.

                                       FOSTER WHEELER LTD.

                                       By:      /s/Thomas R. O'Brien
                                           -------------------------------------
                                              Name:  Thomas R. O'Brien
                                              Title: Senior Vice President

Accepted and Agreed:

BNY MIDWEST TRUST COMPANY,
     as Guarantee Trustee

By:      /s/C. Potter
    ----------------------------------------
      Name:  C. Potter
      Title: Assistant Vice President

                                      -3-<PAGE>

                                                                     Exhibit 4.2

                          SECOND SUPPLEMENTAL INDENTURE

         SECOND SUPPLEMENTAL INDENTURE, dated as of March 15, 2003, made by and
among Foster Wheeler Ltd., a company incorporated under the laws of Bermuda (the
"Guarantor") in favor of the FW Preferred Capital Trust I, a business trust
organized under the laws of Delaware (the "Trust") the Company and BNY Midwest
Trust Company, an Illinois trust company, as Trustee (the "Trustee") and
successor to the obligations of Harris Trust and Savings Bank, an Illinois
banking corporation.

                                W I T E S S E T H

         WHEREAS, pursuant to a declaration of trust, dated as of May 8, 1998,
executed by Foster Wheeler LLC (as successor to Foster Wheeler Corporation by
operation of merger), a limited liability company organized under the laws of
Delaware, (the "Company") and the trustees of the Trust, the Trust has issued
9.00% Preferred Securities, Series I (liquidation amount $25 per preferred
security) (the "Trust Preferred Securities");

         WHEREAS, in connection with the issuance by the Trust of the Trust
Preferred Securities, the Company issued $175,000,000 of junior subordinated
debentures (the "Debentures") to the Trust pursuant to a Junior Subordinated
Indenture, dated as of January 13, 1999, with the Trustee, as amended and
supplemented by the First Supplemental Indenture dated as of January 13, 1999
(as so amended and supplemented, the "Indenture");

         WHEREAS, Section 9.01 of the Indenture provides that the Company and
the Trustee may from time to time amend the Indenture without the consent of the
Holders to make any change that does not adversely affect the rights of any such
Holder in any material respect;

         WHEREAS, the Company and the Guarantor desire that the Guarantor shall
fully and unconditionally guarantee the obligations of the Company under the
Debentures (the "Guarantee"); and

         WHEREAS, all conditions precedent to amend the Indenture have been met.

         NOW, THEREFORE, in consideration of the foregoing and other benefits
accruing to the Guarantor, the receipt and sufficiency of which are hereby
acknowledged, the Guarantor hereby makes the following representations and
warranties to the Trust and hereby covenants and agrees with the Trust as
follows:

         1. Guarantee. The Guarantor fully and unconditionally guarantees the
obligations of the Company in respect of the Debentures and under the Indenture.

         2. Subordination. The Guarantee shall be subordinated and junior in
right of payment to all indebtedness of the Guarantor, whether such indebtedness
is outstanding on the date hereof or thereafter incurred, to the same extent and
in the same manner as the Company's obligations on the Debentures are
subordinated pursuant to the terms of Article XV of the Indenture.

         3. Indenture Effective. Except as amended and supplemented hereby, the
Indenture is hereby ratified and confirmed in all respects and shall remain in
full force and effect.

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         4. Binding Effect. The Guarantee shall be binding upon the Guarantor
and its respective successors and assigns and shall inure to the benefit of the
Trust and its successors and assigns.

         5. Amendment; Discharge. Neither the Guarantee nor any provision of
this Second Supplemental Indenture may be changed, waived, discharged or
terminated orally, but only by an instrument in writing signed by the parties
hereto.

         7. Notices. All notices provided hereunder shall be deemed made when
delivered to the principal executive offices of the party to be notified.

         8. Governing Law. This Second Supplemental Indenture shall be governed
by and construed in accordance with the internal laws of the State of New York
applicable to agreements made and to be performed entirely within such State,
without regard to the conflicts of law principles of such State.

         9. Trustee. The Trustee makes no representations as to the validity or
sufficiency of this Second Supplemental Indenture. The statements and recitals
herein are deemed to be those of the Company and the Guarantor and not of the
Trustee.

                                      -2-
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         IN WITNESS WHEREOF, the Company and the Guarantor have caused this
Second Supplemental Indenture to be executed and delivered as of the date first
written above.

                                      FOSTER WHEELER LLC

                                      By:      /s/Robert D. Iseman
                                         ---------------------------------------
                                          Name:  Robert D. Iseman
                                          Title: Vice President

                                      FOSTER WHEELER LTD., as Guarantor,

                                      By:      /s/Thomas R. O'Brien
                                          --------------------------------------
                                             Name:  Thomas R. O'Brien
                                             Title: Senior Vice President

Accepted and Agreed:

BNY MIDWEST TRUST COMPANY, as Indenture Trustee

By:      /s/C. Potter
    ----------------------------------------
      Name:  C. Potter
      Title: Assistant Vice President

                                      -3-

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