Exhibit 3.1

RESTATED CERTIFICATE OF INCORPORATION

OF

SPECTRA ENERGY CORP

FIRST. The name of the corporation is “Spectra Energy Corp”.

SECOND. The address of the corporation’s registered office in the State of Delaware is Corporation Service Company, 2711 Centerville Road, Suite 400 in the City of Wilmington, County of New Castle, 19808. The name of its registered agent at such address is Corporation Service Company.

THIRD. The purpose of the corporation is to engage in any lawful act or activity for which corporations may be organized under the General Corporation Law of Delaware.

FOURTH. The total number of shares of all classes of stock which the corporation shall have authority to issue is 1,000,001,000, of which 1,000,000,000 shares, par value $0.001 per share, shall be designated as Common Stock and 1,000 shares, par value $0.001, per share shall be designated as Preferred Stock. Shares of Preferred Stock may be issued in one or more series from time to time by the board of directors, and the board of directors is expressly authorized to fix by resolution or resolutions the designations and the powers, preferences and rights, and the qualifications, limitations and restrictions thereof, of the shares of each series of Preferred Stock.

Unless otherwise provided in the resolution or resolutions of the board of directors establishing the terms of a series of Preferred Stock, no holder of any share of Preferred Stock shall be entitled as of right to vote on any amendment or alteration of the Certificate of Incorporation to authorize or create, or increase the authorized amount of, any other class or series of Preferred Stock or any alteration, amendment or repeal of any provision of any other series of Preferred Stock that does not adversely affect in any material respect the rights of the series of Preferred Stock held by such holder.

Except as otherwise required by the General Corporation Law of Delaware or provided in the resolution or resolutions of the board of directors establishing the terms of a series of Preferred Stock, no holder of Common Stock, as such, shall be entitled to vote on any amendment or alteration of the Certificate of Incorporation that alters, amends or changes the powers, preferences, rights or other terms of one or more outstanding series of Preferred Stock if the holders of such affected series are entitled, either separately or together with the holders of one or more other series of Preferred Stock, to vote thereon pursuant to the Certificate of Incorporation or pursuant to the General Corporation Law of Delaware.

Subject to the rights of the holders of any series of Preferred Stock, the number of authorized shares of any class or series of Preferred Stock may be increased or decreased

(but not below the number of shares thereof then outstanding) by the affirmative vote of the holders of a majority of the outstanding shares of such class or series, voting together as a single class, irrespective of the provisions of Section 242(b)(2) of the General Corporation Law of Delaware or any corresponding provision hereafter enacted.

FIFTH. The board of directors of the corporation is expressly authorized to adopt, amend or repeal bylaws of the corporation.

SIXTH. Elections of directors need not be by written ballot except and to the extent provided in the bylaws of the corporation.

SEVENTH. Any action required or permitted to be taken by the holders of Common Stock of the corporation, including but not limited to the election of directors, may be taken by written consent or consents but only if such consent or consents are signed by all holders of Common Stock.

EIGHTH. A director of the corporation shall not be liable to the corporation or its stockholders for monetary damages for breach of fiduciary duty as a director, except to the extent that such exemption from liability or limitation thereof is not permitted under the Delaware General Corporation Law as currently in effect or as the same may hereafter be amended. No amendment, modification or repeal of this Article EIGHTH shall adversely affect any right or protection of a director that exists at the time of such amendment, modification or repeal.