REGISTRATION RIGHTS AGREEMENT CROSSTEX ENERGY, L.P.

Exhibit 4.1

Execution Copy

REGISTRATION RIGHTS AGREEMENT

by and between

CROSSTEX ENERGY, L.P.

and

KAYNE ANDERSON MLP INVESTMENT COMPANY,

TORTOISE ENERGY CAPITAL CORPORATION

and

TORTOISE ENERGY INFRASTRUCTURE CORPORATION

Table of Contents

REGISTRATION RIGHTS AGREEMENT

     THIS REGISTRATION RIGHTS AGREEMENT (this “ Agreement ”) is made and entered into as of June 24, 2005 by and between CROSSTEX ENERGY, L.P., a Delaware limited partnership (“ Crosstex ”), and each of the parties set forth on Schedule A hereto (the “ Purchasers ”).

     WHEREAS, this Agreement is made in connection with the Closing of the issuance and sale of the Purchased Units pursuant to the Senior Subordinated Unit Purchase Agreement, dated as of June 24, 2005, by and between Crosstex and the Purchasers (the “ Purchase Agreement ”);

     WHEREAS, Crosstex has agreed to provide the registration and other rights set forth in this Agreement for the benefit of the Purchasers pursuant to the Purchase Agreement; and

     WHEREAS, it is a condition to the obligations of the Purchasers and Crosstex under the Purchase Agreement that this Agreement be executed and delivered.

     NOW THEREFORE, in consideration of the mutual covenants and agreements set forth herein and for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged by each party hereto, the parties hereby agree as follows:

ARTICLE I
DEFINITIONS

     Section 1.1 Definitions . The terms set forth below are used herein as so defined:

          “ Affiliate ” means, with respect to a specified Person, any other Person, directly or indirectly controlling, controlled by or under direct or indirect common control with such specified Person. For purposes of this definition, “control” (including, with correlative meanings, “controlling”, “controlled by”, and “under common control with”) means the power to direct or cause the direction of the management and policies of such Person, directly or indirectly, whether through the ownership of voting securities, by contract or otherwise.

          “ Business Day ” means any day other than a Saturday, Sunday, or a legal holiday for commercial banks in Houston, Texas.

          “ Closing ” shall have the meaning set forth in the Purchase Agreement.

          “ Closing Date ” shall have the meaning set forth in the Purchase Agreement.

          “ Commission ” means the United States Securities and Exchange Commission.

          “ Common Units ” shall have the meaning set forth in the Purchase Agreement.

          “ Crosstex ” has the meaning specified therefor in the introductory paragraph of this Agreement.

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          “ Effectiveness Period ” has the meaning specified therefor in Section 2.1(a) of this Agreement.

          “ Exchange Act ” shall mean the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission promulgated thereunder.

          “ Holder ” means the record holder of any Registrable Securities.

          “ Included Registrable Securities ” has the meaning specified therefor in Section 2.2(a) of this Agreement.

          “ Losses ” has the meaning specified therefor in Section 2.8(a) of this Agreement.

          “ Managing Underwriter ” means, with respect to any Underwritten Offering, the book running lead manager of such Underwritten Offering.

          “ Non-Disclosure Agreement ” means the non-disclosure agreement between Crosstex and the Kayne Anderson MLP Investment Company dated April 30, 2005 and the non-disclosure agreement between Crosstex and Tortoise Energy Capital Corporation dated April 29, 2005, collectively.

          “ Other Holder ” has the meaning specified in Section 2.2(b) .

          “ Person ” means any individual, corporation, company, voluntary association, partnership, joint venture, trust, limited liability company, unincorporated organization, government or any agency, instrumentality or political subdivision thereof, or any other form of entity.

          “ Piggyback Registration ” has the meaning specified therefor in Section 2.2(a) of this Agreement.

          “ Purchase Agreement ” has the meaning specified therefor in the Recitals of this Agreement.

          “ Purchased Units ” shall have the meaning set forth in the Purchase Agreement.

          “ Purchasers ” has the meaning specified therefor in the introductory paragraph of this Agreement.

          “ Registrable Securities ” means the Common Units to be issued upon conversion of the Purchased Units, all of which are subject to the rights provided herein until such rights terminate pursuant to the provisions of this Agreement.

          “ Registration Expenses ” has the meaning specified therefor in Section 2.7(a) of this Agreement.

          “ Securities Act ” means the Securities Act of 1933, as amended, and the rules and regulations of the Commission promulgated thereunder.

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          “ Selling Expenses ” has the meaning specified therefor in Section 2.7(a) of this Agreement.

          “ Selling Holder ” means a Holder who is selling Registrable Securities pursuant to a registration statement.

          “ Shelf Registration Statement ” means a registration statement under the Securities Act to permit the resale of the Registrable Securities from time to time as permitted by Rule 415 of the Securities Act (or any similar provision then in force under the Securities Act).

          “ Underwritten Offering ” means an offering (including an offering pursuant to a Shelf Registration Statement) in which Common Units are sold to an underwriter on a firm commitment basis for reoffering to the public or an offering that is a “bought deal” with one or more investment banks.

     Section 1.2 Registrable Securities . Any Registrable Security will cease to be a Registrable Security when (a) a registration statement covering such Registrable Security has been declared effective by the Commission and such Registrable Security has been sold or disposed of pursuant to such effective registration statement; (b) such Registrable Security has been disposed of pursuant to any Section of Rule 144 (or any similar provision then in force under the Securities Act); (c) such Registrable Security is held by Crosstex or one of its subsidiaries; (d) such Registrable Security has been sold in a private transaction in which the transferor’s rights under this Agreement are not assigned to the transferee of such securities or (e) two years from the date hereof.

ARTICLE II
REGISTRATION RIGHTS

     Section 2.1 Shelf Registration .

          (a) Shelf Registration . As soon as practicable following the Closing of the acquisition of the Purchased Units pursuant to the terms of the Purchase Agreement, but in any event within 90 days of the Closing, Crosstex shall prepare and file a Shelf Registration Statement. Crosstex shall use its commercially reasonable efforts to cause the Shelf Registration Statement to become effective no later than 180 days after the date of the Closing. A Shelf Registration Statement filed pursuant to this Section 2.1(a) shall be on such appropriate registration form of the Commission as shall be selected by Crosstex; provided, however, that if a prospectus supplement will be used in connection with the marketing of an Underwritten Offering from the Shelf Registration Statement and the Managing Underwriter at any time shall notify Crosstex in writing that, in the sole judgment of such Managing Underwriter, inclusion of detailed information to be used in such prospectus supplement is of material importance to the success of the Underwritten Offering of such Registrable Securities, Crosstex shall use its commercially reasonable efforts to include such information in the prospectus. Crosstex will use its commercially reasonable efforts to cause the Shelf Registration Statement filed pursuant to this Section 2.1(a) to be continuously effective under the Securities Act until the earlier of (i) all Registrable Securities covered by the Shelf Registration Statement have been distributed in the manner set forth and as contemplated in the Shelf Registration Statement or (ii) there are no

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longer any Registrable Securities outstanding (the “ Effectiveness Period ”). The Shelf Registration Statement when declared effective (including the documents incorporated therein by reference) will comply as to form in all material respects with all applicable requirements of the Securities Act and the Exchange Act and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. If the Shelf Registration Statement is not declared effective within 210 days after Closing, then the Purchasers shall be entitled to a payment (with respect to each of such Purchaser’s Purchased Units), as liquidated damages and not as a penalty, of 0.25% of the Purchase Price per 30-day period for the first sixty (60) days following the 210th day after Closing, with such payment amount increasing by an additional 0.25% of the Purchase Price per 30-day period for each subsequent 60 days, up to a maximum of 1.0% of the Purchase Price per 30-day period (the “ Liquidated Damages ”), until such time as the Shelf Registration Statement is declared effective or there are no longer any Registrable Securities outstanding. The Liquidated Damages shall be paid to each Purchaser in cash within ten (10) Business Days of the end of such 30-day period. The Purchasers’ rights (and any transferee’s rights pursuant to Section 2.10) under this Section 2.1 shall terminate when such Registrable Securities become eligible for resale under Rule 144(k) (or any similar provision then in force under the Securities Act).

          (b) Delay Rights . Notwithstanding anything to the contrary contained herein, Crosstex may, upon written notice to any Selling Holder whose Registrable Securities are included in the Shelf Registration Statement, suspend such Selling Holder’s use of any prospectus which is a part of the Shelf Registration Statement (in which event the Selling Holder shall discontinue sales of the Registrable Securities pursuant to the Shelf Registration Statement) if (i) Crosstex is pursuing an acquisition, merger, reorganization, disposition or other similar transaction and Crosstex determines in good faith that Crosstex’s ability to pursue or consummate such a transaction would be materially and adversely affected by any required disclosure of such transaction in the Shelf Registration Statement or (ii) Crosstex has experienced some other material non-public event the disclosure of which at such time, in the good faith judgment of Crosstex, would materially and adversely affect Crosstex; however, in no event shall any delay pursuant hereto exceed sixty (60) days in any one hundred-eighty (180) day period or ninety (90) days in any twelve-month period. Upon disclosure of such information or the termination of the condition described above, Crosstex shall provide prompt notice to the Selling Holders whose Registrable Securities are included in the Shelf Registration Statement, and shall promptly terminate any suspension of sales it has put into effect and shall take such other actions to permit registered sales of Registrable Securities as contemplated in this Agreement.

     Section 2.2 Piggyback Registration .

          (a) Participation . After the Purchased Units have converted into Common Units if Crosstex at any time proposes to file a prospectus supplement to an effective Shelf Registration Statement with respect to an Underwritten Offering of Common Units for its own account or to register any Common Units for its own account for sale to the public in an Underwritten Offering other than (x) a registration relating solely to employee benefit plans, (y) a registration relating solely to a Rule 145 transaction, or (z) a registration on any registration form which does not permit secondary sales, does not include substantially the same information as would be required to be included in a registration statement covering the sale of Registrable

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Securities or would require that Crosstex effectuate a post-effective amendment to such registration statement to permit such Registrable Securities to be covered by the registration statement, then, as soon as practicable following the engagement of counsel to Crosstex to prepare the documents to be used in connection with an Underwritten Offering, Crosstex shall give notice of such proposed Underwritten Offering to the Holders, and such notice shall offer the Holders the opportunity to include in such Underwritten Offering such number of Registrable Securities (the “ Included Registrable Securities ”) as each such Holder may request in writing (a “ Piggyback Registration ”); provided , however , that Crosstex shall not be required to offer such opportunity to Holders if (i) the Holders do not offer a minimum of $5,000,000 of Purchased Units (determined by multiplying the number of Purchased Units offered by the average of the closing price for Common Units for the ten (10) trading days preceding the date of such notice) or (ii) Crosstex has been advised by the Managing Underwriter that the inclusion of Registrable Securities for sale for the benefit of the Holders will have an adverse effect on the price, timing or distribution of the Common Units. The notice required to be provided in this Section 2.2(a) to Holders shall be provided on a Business Day pursuant to Section 3.1 hereof and receipt of such notice shall be confirmed by Holder. Holder shall then have two business days to request inclusion of Registrable Securities in the Underwritten Offering. If no request for inclusion from a Holder is received within the specified time, such Holder shall have no further right to participate in such Piggyback Registration. If, at any time after giving written notice of its intention to undertake an Underwritten Offering and prior to the closing of such Underwritten Offering, Crosstex shall determine for any reason not to undertake or to delay such Underwritten Offering, Crosstex may, at its election, give written notice of such determination to the Selling Holders and, (x) in the case of a determination not to undertake such Underwritten Offering, shall be relieved of its obligation to sell any Included Registrable Securities in connection with such terminated Underwritten Offering, and (y) in the case of a determination to delay such Underwritten Offering, shall be permitted to delay offering any Included Registrable Securities for the same period as the delay in the Underwritten Offering. Any Selling Holder shall have the right to withdraw such Selling Holder’s request for inclusion of such Selling Holder’s Registrable Securities in such offering by giving written notice to Crosstex of such withdrawal up to and including the time of pricing of such offering. No Holders shall be entitled to participate in any such Underwritten Offering under this Section 2.2(a) unless all Holders participating therein hold at least fifteen million ($15,000,000) of Purchased Units (determined by multiplying the number of Purchased Units offered by the average of the closing price for Common Units for the ten (10) trading days preceding the date of such notice).

          (b) Priority of Piggyback Registration . If the Managing Underwriter or Underwriters of any proposed Underwritten Offering of Common Units included in a Piggyback Registration advises Crosstex that the total amount of Common Units which the Selling Holders and any other Persons intend to include in such offering exceeds the number which can be sold in such offering without being likely to have an adverse effect on the price, timing or distribution of the Common Units offered or the market for the Common Units, then the Common Units to be included in such Underwritten Offering shall include the number of Registrable Securities that such Managing Underwriter or Underwriters advises Crosstex can be sold without having such adverse effect, with such number to be allocated pro rata among the Selling Holders and any other Persons who have been or are granted registration rights on or after the date of this Agreement (“ Other Holders ”) who have requested participation in the Piggyback Registration (based, for each such Selling Holder or Other Holder, on the percentage derived by dividing (A)

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the number of Registrable Securities proposed to be sold by such Selling Holder or such Other Holder in such offering; by (B) the aggregate number of Common Units proposed to be sold by all Selling Holders and all Other Holders in the Piggyback Registration.

     Section 2.3 Underwritten Offering .

          (a) S-3 Registration . In the event that a Selling Holder (together with any Affiliate that is a Selling Holder) elects to dispose of Registrable Securities under the Shelf Registration Statement pursuant to an Underwritten Offering of at least fifteen million ($15,000,000) of Common Units, Crosstex shall, at the request of such Selling Holder, enter into an underwriting agreement in customary form with the Managing Underwriter or Underwriters, which shall include, among other provisions, indemnities to the effect and to the extent provided in Section 2.8 , and shall take all such other reasonable actions as are requested by the Managing Underwriter in order to expedite or facilitate the disposition of the Registrable Securities; provided, however, that Crosstex management will not be required to participate in a roadshow or similar marketing effort.

          (b) General Procedures . In connection with any Underwritten Offering (i) under Section 2. 2 of this Agreement, Crosstex shall be entitled to select the Managing Underwriter or Underwriters, and (ii) under Section 2.3 of this Agreement, the Selling Holders shall be entitled to select the Managing Underwriter or Underwriters. In connection with an Underwritten Offering under Section 2.2 or Section 2.3 hereof, each Selling Holder and Crosstex shall be obligated to enter into an underwriting agreement which contains such representations, covenants, indemnities and other rights and obligations as are customary in underwriting agreements for firm commitment offerings of securities. No Selling Holder may participate in such Underwritten Offering unless such Selling Holder agrees to sell its Registrable Securities on the basis provided in such underwriting agreement and completes and executes all questionnaires, powers of attorney, indemnities and other documents reasonably required under the terms of such underwriting agreement. Each Selling Holder may, at its option, require that any or all of the representations and warranties by, and the other agreements on the part of, Crosstex to and for the benefit of such underwriters also be made to and for such Selling Holder’s benefit and that any or all of the conditions precedent to the obligations of such underwriters under such underwriting agreement also be conditions precedent to its obligations. No Selling Holder shall be required to make any representations or warranties to or agreements with Crosstex or the underwriters other than representations, warranties or agreements regarding such Selling Holder and its ownership of the securities being registered on its behalf and its intended method of distribution and any other representation required by law. If any Selling Holder disapproves of the terms of an underwriting, such Selling Holder may elect to withdraw therefrom by notice to Crosstex and the Managing Underwriter; provided , however , that such withdrawal must be made