Exhibit 4.2

FIRST SUPPLEMENTAL INDENTURE

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FIRST SUPPLEMENTAL INDENTURE
dated as of April 20, 2004

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with respect to the
INDENTURE
dated as of March 2, 2000
between

LaBRANCHE & CO INC.,
as Issuer,

and

U.S. BANK, NATIONAL ASSOCIATION,
as Trustee

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FIRST SUPPLEMENTAL INDENTURE dated as of April 20, 2004 (this "Supplemental Indenture") between LaBranche & Co Inc., a Delaware corporation
(the "Company"), and U.S. Bank, National Association, the successor in interest to Firstar Bank, N.A., as trustee (the "Trustee") for the securities issued under the Indenture dated as of
March 2, 2000 between the Company and the Trustee (as amended, supplemented or otherwise modified from time to time, the "Indenture").

RECITALS

WHEREAS, pursuant to and in accordance with the terms of the Indenture, the Company established and issued its 12% Senior Subordinated Notes due 2007 (the
"Notes"); and

WHEREAS,
in accordance with Section 8.2 of the Indenture, the Company has obtained the consent of the Holders of not less than a majority in aggregate principal amount of the
outstanding Notes to the amendments to the Indenture set forth in this Supplemental Indenture.

NOW,
THEREFORE, in consideration of the premises herein contained and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, it is
mutually covenanted and agreed as follows:

AGREEMENTS

Section 1.Defined Terms.Terms defined in the Indenture and not otherwise defined herein are used herein
as therein defined.

Section 2.Current Amendment to the Indenture.Effective as of the date hereof, the last sentence of
Section 8.4(a) of the Indenture, and any corresponding provision of the Notes, is hereby deleted in its entirety.

Section 3.Amendment Effective Date Amendments to the Indenture.Effective as of the Amendment Effective
Date (as defined in Section 14 below):



Existing Article or Section Number

CaptionSection 4.6

Limitation on Incurrence of Additional IndebtednessSection 4.7

Limitation on Restricted PaymentsSection 4.9

Limitation on Distributions and Other Restrictions Affecting SubsidiariesSection 4.10

Limitation on Issuance and Sale of Capital Interests in Restricted SubsidiariesSection 4.11

Limitations on LiensSection 4.12

Limitations on Transactions with AffiliatesSection 4.13

Limitation On Designations of Unrestricted SubsidiariesSection 4.15

Limitation on Layered IndebtednessSection 4.17

Maintenance of Properties and InsuranceArticle V

Successor Corporation


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Section 4.Indenture Ratified.Except as hereby otherwise expressly provided, the Indenture is in all
respects ratified and confirmed, and all the terms, provisions and conditions thereof shall be and remain in full force and effect.

Section 5.Incorporation into Indenture.All provisions of this Supplemental Indenture shall be deemed to
be incorporated in, and made part of, the Indenture, and the Indenture, as amended and supplemented by this First Supplemental Indenture, shall be read, taken and construed as one and the same
instrument.

Section 6.Governing Law.THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, INCLUDING SECTION 5-1401 OF THE GENERAL OBLIGATIONS LAW, BUT OTHERWISE WITHOUT REGARD TO CONFLICT OF LAW
RULES.

Section 7.References to Supplemental Indenture.Any and all notices, requests, certificates and other
instruments executed and delivered after the execution and delivery of this Supplemental Indenture may refer to the Indenture without making specific reference to this Supplemental Indenture, but
nevertheless all such references shall include this Supplemental Indenture unless the context otherwise requires.

Section 8.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.

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Section 9.Trust Indenture Act Controls.If any provision of this Supplemental Indenture qualifies or
conflicts with another provision which is required to be included in this Supplemental Indenture by the Trust Indenture Act, the required provision shall control.

Section 10.Acceptance.The Trustee accepts the Indenture, as supplemented by this Supplemental
Indenture, and agrees to perform the same upon the terms and conditions set forth therein as so supplemented.

Section 11.Trustee Not Responsible for Recitals.The recitals contained herein shall be taken solely as
the statements of the Company, and the Trustee assumes no responsibility for their correctness. The Trustee makes no representations as to the validity or sufficiency of this Supplemental Indenture.

Section 12.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.

Section 13.Headings.The headings of the Sections 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.

Section 14.Effectiveness.This Supplemental Indenture shall become effective upon execution by the
Company and the Trustee. As used herein, the "Amendment Effective Date" shall mean the date that the Company delivers written notice to the Trustee that the Notes tendered and not validly withdrawn
pursuant to the Company's Offer to Purchase and Consent Solicitation Statement dated April 5, 2004, as amended, have been accepted for purchase.

[Signature
Page Follows]

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

| |  | LaBranche & Co Inc.                        
| |  | -------------------------------------------
| |  | By:                                        
| |  | U.S. Bank, National Association,
as Trustee
| |  | By:                                        

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