REGISTRATION RIGHTS AGREEMENT

Exhibit 10.4

EXECUTION VERSION

REGISTRATION RIGHTS AGREEMENT

This REGISTRATION RIGHTS AGREEMENT, dated as of March 31, 2008 (this “Agreement” ), is made by and between BGC Partners, LLC, a Delaware limited liability company ( “BGC Partners” ), and Cantor Fitzgerald, L.P., a Delaware limited partnership ( “Cantor” ).

W I T N E S S E T H:

WHEREAS, Cantor and BGC Partners have entered into the Separation Agreement, dated as of March 31, 2008 (as amended from time to time, the “Separation Agreement” ), with BGC Partners, L.P., a Delaware limited partnership ( “U.S. Opco” ), BGC Global Holdings, L.P., a Cayman Islands limited partnership ( “Global Opco” ), and BGC Holdings, L.P., a Delaware limited partnership ( “Holdings” ), to effect the Contribution (as defined in the Separation Agreement).

WHEREAS, as part of the Contribution, Cantor received or is entitled to receive BGC Partners Common Stock (as defined below) in conjunction with the Contribution and upon exchange of Holdings Exchangeable Limited Partnership Interests (as defined below).

WHEREAS, Cantor and BGC Partners desire to enter into this Agreement to set forth the terms and conditions of the registration rights and obligations of the Cantor and BGC Partners and their respective Affiliates and certain transferees of Securities to be held by Cantor or its Affiliates;

NOW, THEREFORE, in consideration of the premises and the covenants hereinafter contained, it is agreed as follows:

ARTICLE I

DEFINITIONS

SECTION 1.1  Definitions . As used in this Agreement, the following capitalized terms shall have the meanings ascribed to them below:

“Affiliate” means, with respect to any Person, any other Person that directly, or through one or more intermediaries, controls or is controlled by or is under common control with such Person. For the purposes of this definition, “control” with respect to any Person means, the direct or indirect possession of the power to direct or cause the direction of the management or policies of such Person, whether through the ownership of voting securities, by Contract or otherwise; and the terms “controlling” and “controlled” have meanings correlative to the foregoing.

“Article III Notice” has the meaning set forth in Section 3.1.

“BGC Partners” has the meaning set forth in the preamble (it being understood that, after the Merger Effective Time, each reference to BGC Partners in this Agreement shall refer to the Surviving Company).

“BGC Partners Free Writing Prospectus” means each Free Writing Prospectus prepared by or on behalf of BGC Partners other than a Cantor Free Writing Prospectus.

“Business Day” means any day other than a Saturday, Sunday or a day on which banks are authorized or required to be closed for business in New York City, New York, United States of America.

“BGC Partners Class A Common Stock” means the Class A common stock, par value $0.01 per share, of BGC Partners.

“BGC Partners Class B Common Stock” means the Class B common stock, par value $0.01 per share, of BGC Partners.

“BGC Partners Common Stock” means the BGC Partners Class A Common Stock and the BGC Partners Class B Common Stock, as applicable.

“BGC Partners Person” has the meaning set forth in Section 6.2.

“Cantor” has the meaning set forth in the preamble.

“Cantor Free Writing Prospectus” means each Free Writing Prospectus prepared by or on behalf of (unless prepared by BGC Partners or on behalf of BGC Partners) the relevant member of the Cantor Group and used or referred to by such member of the Cantor Group in connection with the offering of Registrable Securities.

“Cantor Group” means “Cantor Group” as defined in the Separation Agreement.

“Closing” means “Closing” as defined in the Separation Agreement.

“Damages” has the meaning set forth in Section 6.1.

“Demand Request” has the meaning set forth in Section 2.1.

“Demand Registration” has the meaning set forth in Section 2.1.

“Disclosure Package” means, with respect to any offering of securities, (i) the preliminary Prospectus, (ii) each BGC Partners Free Writing Prospectus (if any) and (iii) all other information prepared by or on behalf of BGC Partners, in each case, that is deemed under Rule 159 promulgated under the Securities Act to have been conveyed to purchasers of securities at the time of sale of such securities (including a contract of sale).

“Exchange Act” means the U.S. Securities Exchange Act of 1934, as from time to time amended, and the rules and regulations of the SEC promulgated thereunder.

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“Free Writing Prospectus” means any “free writing prospectus” as defined in Rule 405 promulgated under the Securities Act.

“Global Opco” has the meaning set forth in the recitals hereto.

“Holder” shall mean Cantor and any Affiliate of Cantor holding Registrable Securities, in each case so long as such Holder holds Registrable Securities.

“Holder Covered Persons” has the meaning set forth in Section 6.1.

“Holdings” has the meaning set forth in the recitals hereto.

“Holdings Exchangeable Limited Partnership Interest” means an “Exchangeable Limited Partnership Interest” as defined in the New Holdings Limited Partnership Agreement.

“Indemnified Party” has the meaning set forth in Section 6.3.

“Indemnifying Party” has the meaning set forth in Section 6.3.

“Merger” means the merger of BGC Partners and eSpeed set forth in the Merger Agreement.

“Merger Agreement” means the Agreement and Plan of Merger, dated as of May 29, 2007, among BGC Partners, Holdings, eSpeed, Inc., a Delaware corporation, U.S. Opco and Global Opco.

“Merger Effective Time” means “Effective Time” as defined in the Merger Agreement.

“New Holdings Limited Partnership Agreement” means the Amended and Restated Limited Partnership Agreement of BGC Holdings, L.P., as amended from time to time.

“Person” means any individual, firm, corporation, partnership, trust, incorporated or unincorporated association, joint venture, joint stock company, limited liability company, Governmental Entity or other entity of any kind, and shall include any successor (by merger or otherwise) of such entity.

“Piggy-back Registration” has the meaning set forth in Section 3.1.

“Prospectus” means the prospectus included in any Registration Statement, as amended or supplemented by any prospectus supplement with respect to the terms of the offering of any portion of the Registrable Securities covered by such Registration Statement or any other amendments and supplements to such prospectus, including without limitation any preliminary prospectus, any pre-effective or post-effective amendment and all material incorporated by reference in any prospectus.

“Public Offering” has the meaning set forth in Section 3.1.

“Registrable Securities” means shares of BGC Partners Common Stock which are issued or transferred or issued to any Holder pursuant to and in accordance with the New Holdings

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Limited Partnership Agreement, and any shares of BGC Partners Common Stock issued or issuable in respect of or in exchange for any such shares of BGC Partners Common Stock. As to any particular Registrable Securities, once issued such securities shall cease to be Registrable Securities when (i) a Registration Statement with respect to the sale of such securities shall have become effective under the Securities Act and such securities shall have been disposed of in accordance with such Registration Statement, (ii) such securities shall have been sold to the public pursuant to Rule 144 (or any successor provision) under the Securities Act, (iii) such securities shall have ceased to be outstanding, or (iv) such securities may be sold in the public market of the United States, in unlimited amounts, under Rule 144(k), without registration under the Securities Act. For any calculations relating to Registrable Securities herein, the Holdings Exchangeable Limited Partnership Interests are counted as the number of shares of BGC Partners Common Stock issuable in respect of such Holdings Exchangeable Limited Partnership Interests (whether or not issued), in accordance with the New Holdings Limited Partnership Agreement.

“Registration Expenses” has the meaning set forth in Section 5.1.

“Registration Statement” means any registration statement of BGC Partners which covers Registrable Securities pursuant to the provisions of this Agreement, all amendments and supplements to such registration statement, including post-effective amendments, and all exhibits and all material incorporated by reference in such registration statement.

“Rule 144” has the meaning set forth in Section 7.1.

“SEC” means the U.S. Securities and Exchange Commission.

“Securities Act” means the U.S. Securities Act of 1933, as from time to time amended, and the rules and regulations of the SEC promulgated thereunder.

“Separation Agreement” has the meaning set forth in the recitals hereto.

“Surviving Company” means the surviving entity in the Merger.

“U.S. Opco” has the meaning set forth in the recitals hereto.

ARTICLE II

DEMAND REGISTRATIONS

SECTION 2.1  Requests for Registration . Subject to the provisions of this Article II, any Holder or group of Holders may at any time make a written request (a “Demand Request” ) for registration under the Securities Act of a number of shares of Registrable Securities that (1) represents at least 10% of the shares of BGC Class A Common Stock outstanding on the date of the Demand Request or (2) has an aggregate market value on the date of the Demand Request of greater than $20 million (such written Request, a “Demand Registration” ). Such Demand Requests shall specify the amount of Registrable Securities to be registered and the intended method or methods of disposition. BGC Partners shall, subject to the provisions of this Article II and to the Holders’ compliance with their obligations under the provisions of this Agreement, as promptly as practicable register under the Securities Act all Registrable Securities included in such Demand Request, for disposition in accordance with the intended method or methods set

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forth therein; provided that if the managing underwriter(s) for a Demand Registration in which Registrable Securities are proposed to be included pursuant to this Article II that involves an underwritten offering shall advise BGC Partners that in its reasonable opinion, the number of Registrable Securities to be sold is greater than the amount that can be offered without adversely affecting the success of the offering (taking into consideration the interests of BGC Partners and the Holders), then BGC Partners will be entitled to reduce the number of Registrable Securities included in such registration to the number that, in the opinion of the managing underwriter(s), can be sold without having the adverse effect referred to above. The number of Registrable Securities that may be registered shall be allocated in the following priority: first , pro rata among the Holders participating in the Demand Registration, based on the number of Registrable Securities included by such Holder in the Demand Request; second , all shares of BGC Partners Common Stock proposed to be registered for offer and sale by BGC Partners; and third , to shares of BGC Partners Common Stock proposed to be registered pursuant to any piggy-back registration rights of third parties. As promptly as practicable thereafter, but subject to Section 2.3 hereof, BGC Partners shall use its reasonable best efforts to file with the SEC a Registration Statement, registering all Registrable Securities that any Holders have requested to register, for disposition in accordance with the intended method or methods set forth in their notices to BGC Partners. BGC Partners shall use its reasonable best efforts to cause such Registration Statement to be declared effective as soon as practicable after filing and to remain effective until the earlier of (i) 90 days following the date on which it was declared effective and (ii) the date on which all of the Registrable Securities covered thereby are disposed of in accordance with the method or methods of disposition stated therein. Each Demand Request shall be irrevocable except as otherwise expressly provided herein (including Section 2.4).

Notwithstanding anything to the contrary in this Article II, no Holder shall have the right to require BGC Partners to register any Registrable Securities pursuant to this Article II during any period (not to exceed 180 days) following the closing of the completion of a distribution of securities offered by BGC Partners that would cause BGC Partners to breach a lock-up provision contained in the underwriting agreement for such distribution.

SECTION 2.2  Number and Timing of Registrations . Notwithstanding anything in this Article II to the contrary: (a) the Holders shall be entitled to make no more than four Demand Registrations hereunder (and no more than one Demand Registration during any twelve-month period), and (b) BGC Partners shall not be obligated to make a Demand Registration in the event that a Piggy-back Registration had been available to any Holder within the 180 days preceding the date of the Demand Request.

SECTION 2.3  Suspension of Registration . Notwithstanding the foregoing, if in the good faith judgment of the Board of Directors of BGC Partners it would be materially detrimental to BGC Partners and its stockholders for any Registration Statement to be filed or for any Registration Statement or Prospectus to be amended or supplemented because such filing, amendment or supplement would (i) require disclosure of material non-public information, the disclosure of which would be reasonably likely to materially and adversely affect BGC Partners and its subsidiaries (if any) taken as a whole, or (ii) materially interfere with any existing or prospective business situation, transaction or negotiation involving BGC Partners, BGC Partners shall have the right to suspend the use of the applicable Registration Statement or delay delivery or filing, but not the preparation, of the applicable Registration Statement or Prospectus or any

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document incorporated therein by reference, in each case for a reasonable period of time; provided , however , that BGC Partners shall not be able to exercise such suspension right more than twice in each 12-month period aggregating not more than 150 days in such 12-month period. In the event that the ability of the Holders to sell shall be suspended for any reason, the period of such suspension shall not count towards compliance with the 90-day period referred to under clause (i), of Section 2.1 of this Agreement.

SECTION 2.4  Interrupted Registration . A registration requested pursuant to this Article II shall not be deemed to have been requested by the Holders of Registrable Securities for purposes of Section 2.2: (i) unless it has been declared effective by the SEC; (ii) if after it has become effective, such registration is interfered with by any stop order, injunction or other order or requirement of the SEC for any reason other than misrepresentation or an omission by the requesting Holders such that the Registration Statement shall not be effective until the earlier of (A) 60 days following the date on which it was declared effective (treating any suspension or interruption of registration as provided in Section 2.3) and (B) the date on which all of the Registrable Securities covered thereby are disposed of in accordance with the method or methods of disposition stated therein; (iii) if the conditions to closing specified in the underwriting agreement, if any, entered into in connection with such registration are not satisfied other than by reason of some wrongful act or omission, or act or omission in bad faith, by such Holders and are not otherwise waived; or (iv) if such request has been withdrawn by the requesting Holders and such Holders shall have elected to pay all Registration Expenses of BGC Partners in connection with such withdrawn request.

ARTICLE III

PIGGY-BACK REGISTRATIONS

SECTION 3.1  Right to Include Registrable Securities . If at any time following the Merger Effective Time, BGC Partners proposes to register (including for this purpose a registration effected by BGC Partners for security holders of BGC Partners other than any Holder) any Registrable Securities and to file a Registration Statement with respect thereto under the Securities Act, whether or not for sale for its own account (other than pursuant to (i) Section 2.1, (ii) a registration statement on Form S-4, Form S-8 or any successor or similar forms, or (iii) a registration statement for the sales of Registrable Securities issuable or issued upon exchange, conversion or sale of any Holdings Exchangeable Limited Partnership Interests held by any member of the Cantor Group), in a manner that would permit registration of Registrable Securities for sale to the public under the Securities Act (a “Public Offering” ), BGC Partners will each such time promptly give written notice to the Holders (i) of its intention to do so, (ii) of the form of registration statement of the SEC that has been selected by BGC Partners and (iii) of rights of Holders under this Article III (the “Article III Notice” ). BGC Partners will include in the case of a proposed Public Offering all Registrable Securities that BGC Partners is requested in writing, within 15 days after the Article III Notice is given, to register by the Holders thereof (each, a “Piggy-back Registration” ); provided , however , that (x) if, at any time after giving written notice of its intention to register any Registrable Securities and prior to the effective date of the Registration Statement filed in connection with such registration, BGC Partners shall determine that none of such Registrable Shares shall be registered, BGC Partners may, at its election, give written notice of such determination to all Holders who so requested registration and, thereupon, shall be relieved of its obligation to register any Registrable Securities in

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connection with such abandoned registration, without prejudice, however, to the rights of Holders under Article II hereof, and (y) in case of a determination by BGC Partners to delay registration of the Registrable Securities, BGC Partners shall be permitted to delay the registration of such Registrable Securities pursuant to this Article III for the same period as the delay in registering such other Registrable Securities by BGC Partners, as the case may be or may abandon the registration of Registrable Securities, in the sole discretion of BGC Partners. No registration effected under this Article III shall relieve BGC Partners of its obligations to effect registrations upon request under Article II.

SECTION 3.2  Priority; Registration Form . If the managing underwriter(s) for a registration in which Registrable Securities are proposed to be included pursuant to this Article III that involves an underwritten offering shall advise BGC Partners in good faith that in its opinion, the number of shares of BGC Partners Common Stock to be sold for the account of persons other than BGC Partners (collectively, “Selling Stockholders” is greater than the amount that can be offered without adversely affecting the success of the offering (taking into consideration the interests of BGC Partners and the Holders), then the number of shares of BGC Partners Common Stock to be sold for the account of Selling Stockholders (including Holders of Registrable Securities) may be reduced to a number that, in the reasonable opinion of the managing underwriter(s), may reasonably be sold without having the adverse effect referred to above. The reduced number of shares of BGC Partners Common Stock that may be registered shall be allocated in the case of a Public Offering, in the following priority: first , to shares of BGC Partners Common Stock proposed to be registered for offer and sale by BGC Partners; second , to shares of BGC Partners Common Stock proposed to be registered pursuant to any demand registration rights of third parties; and, third , to Registrable Securities proposed to be registered by Holders as a Piggy-back Registration. The reduced number of Registrable Securities that may be registered pursuant to this Section 3.2 shall be allocated pro rata among the Holders participating in the Piggy-back Registration, based on the number of Registrable Securities beneficially owned by the respective Holders. If, as a result of the proration provisions of this Section 3.2, any Holder shall not be entitled to include all Registrable Securities in a registration pursuant to this Article III that such Holder has requested be included, such Holder may elect to withdraw its Registrable Securities from the registration.

ARTICLE IV

REGISTRATION PROCEDURES

SECTION 4.1  Use Reasonable Best Efforts . In connection with BGC Partners’ registration obligations pursuant to Article II and Article III hereof, BGC Partners shall use its reasonable best efforts to effect such registrations to permit the sale of such Registrable Securities in accordance with the intended method or methods of disposition thereof and pursuant thereto BGC Partners shall as expeditiously as reasonably practicable:

(a) prepare and file with the SEC a Registration Statement or Registration Statements relating to the registration on any appropriate form under the Securities Act, and to cause such Registration Statement to become effective as soon as reasonably practicable and to remain continuously effective for the time period required by this Agreement to the extent permitted under the Securities Act;

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(b) prepare and file with the SEC such amendments and post-effective amendments to each Registration Statement as may be necessary to keep such Registration Statement effective for the applicable period set forth in Section 2.1; and to cause the Registration Statement and the related Prospectus to be supplemented by any required Prospectus supplement, and as so supplemented to be filed in accordance with the Securities Act and any rules and regulations promulgated thereunder; and otherwise to comply with the provisions of the Securities Act as may be necessary to facilitate the disposition of all Registrable Securities covered by such Registration Statement during the applicable period in accordance with the intended method or methods of disposition by the selling Holders thereof set forth in such Registration Statement or such Prospectus or Prospectus supplement;

(c) notify the selling Holders and the managing underwriter(s), if any, promptly if at any time (i) any Prospectus, Registration Statement or amendment or supplement thereto is filed, (ii) any Registration Statement, or any post-effective amendment thereto, becomes effective, (iii) the SEC or any other federal or state governmental authority requests any amendment or supplement to, or any additional information in respect of, any Registration Statement or Prospectus, (iv) the SEC or any other federal or state governmental authority issues any stop order suspending the effectiveness of a Registration Statement or initiates any proceedings for that purpose, (v) BGC Partners receives any notice that the qualification of any Registrable Securities for sale in any jurisdiction has been suspended or that any proceeding has been initiated for the purpose of suspending such qualification (vi) upon the discovery of any event which requires that any changes be made in such Registration Statement or any related Prospectus so that such Registration Statement or Prospectus will not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, in light of the circumstances under which they were made; provided , however , that in the case of this subclause (vi), such notice need only state