SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16 of

the Securities Exchange Act of 1934

For the month of ~~June~~July, 2006

Commission File Number: 333-132076

GAS NATURAL SDG, S.A.

(Translation of Registrant’s Name into English)

Av. Portal de L’Angel, 20-22

08002 Barcelona, Spain

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file

annual reports under cover Form 20-F or Form 40-F:

Form 20-F x Form 40-F ¨

Indicate by check mark if the registrant is submitting the Form 6-K

in paper as permitted by Regulation S-T Rule 101(b)(1):

Yes ¨ No x

Indicate by check mark if the registrant is submitting the Form 6-K

in paper as permitted by Regulation S-T Rule 101(b)(7):

Yes ¨ No x

Indicate by check mark whether by furnishing the information

contained in this Form, the Registrant is also thereby furnishing the information to the

Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934:

Yes ¨ No x

If “Yes” is marked, indicate below the file number assigned to the registrant

in connection with Rule 12g3-2(b): N/A

This is a translation of a Spanish language ~~press~~relevant ~~release~~fact.

In case of discrepancies, the Spanish version will prevail.

GAS NATURAL SDG, S.A.

~~Payment~~Gas Natural SDG, S.A., in accordance with Section 2.2.1 (“Consideration”) of ~~dividend~~Chapter II of the Spanish prospectus (Folleto Explicativo) regarding the offer for the shares of Endesa, S.A., approved by the Comisión Nacional del Mercado de Valores on February 27, 2006,

~~The~~NOTIFIES ~~General~~THAT ~~Meeting of Shareholders, held on June 8, 2006, resolved to distribute a complementary dividend for fiscal year 2005, in accordance with the following:~~

~~Amount~~As provided in Section 2.2.1 of the Spanish prospectus regarding the offer by Gas Natural SDG, S.A. for the shares of Endesa, S.A. (the “Offer”), the consideration set forth in the Offer has been automatically adjusted as a result of today’s payment of a complementary dividend in the gross amount of 2.095 euros per share, approved by the Ordinary General Meeting of Shareholders of Endesa, S.A. on February 25, 2006.

~~Gross~~Pursuant ~~dividend~~to the Spanish prospectus regarding the Offer, the consideration initially offered was 7,340 euros and 569 shares of Gas Natural SDG for every 1,000 shares of Endesa, S.A., or 7.34 euros and 0.53569 shares of Gas Natural SDG, S.A. for every share of Endesa, S.A. This consideration is now automatically reduced by an amount equal to the gross value of the excess of such dividend approved by the Ordinary Meeting of Shareholders of Endesa, S.A. which is not in conformity with the company’s dividend policy (as announced in the Registration of Shares Document, Documento de Registro de Acciones, of Endesa, S.A. filed with the Comisión Nacional del Mercado de Valores on July 7, 2005), i.e., by 1,357 euros for every 1,000 shares of Endesa, S.A., or likewise, by 1.357 euros for each share of Endesa, S.A.

~~Withholding~~As a result of the above, the adjusted consideration is 5,983 euros and 569 shares of Gas Natural SDG, S.A. for ~~individual~~every ~~income~~1,000 ~~tax~~shares ~~will~~of ~~apply~~Endesa, toS.A., ~~this~~or ~~amount~~0.569 newly issued shares of Gas Natural SDG, ~~pursuant~~S.A. and 5.983 euros for each share of Endesa, S.A. Therefore, all references to the ~~applicable~~consideration ~~laws~~ contained in ~~effect~~the onSpanish prospectus regarding the ~~due~~Offer ~~date~~must be deemed to henceforth refer to the adjusted consideration as detailed in this communication.

~~Payment~~In ~~date~~any event, the Board of Directors of Gas Natural SDG, S.A. reserves the right to adopt in the future the decisions that it considers appropriate with respect to the consideration contained in the Offer within the terms provided by the laws in effect.

Barcelona, July 43, 2006

Form of payment

As the shares of the company are represented in book-entry form, this dividend will be paid in accordance with the laws in effect for the participating entities, using the methods made available for such entities by the Sociedad de Gestión de los Sistemas de Registro, Compensación y Liquidación de Valores, S.A. (“Iberclear”). For that purpose, the Caja de Ahorros y Pensiones de Barcelona (“La Caixa”) is appointed as payment agent.

Barcelona, June 28, 2006

Chairman of the Board of Directors

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	GAS NATURAL SDG, S.A.
Date: June 28, 2006	By:	/s/ Carlos J. Álvarez Fernández
Date: July 3, 2006	By:	/s/ Carlos J. Álvarez Fernández
		Name:	Carlos J. Álvarez Fernández
		Title:	Chief Financial Officer

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