The $38 billion takeover of Anadarko Petroleum Corp. by rival independent oil and gas company Occidental Petroleum Corp. on June 4 received approval by the U.S. Federal Trade Commission (FTC).

Anadarko, based in The Woodlands, Texas, agreed to the acquisition by Houston-based Occidental in early May. The agreement ended a nearly month-long takeover battle for Anadarko between Occidental and Chevron Corp.

Some of Occidental’s shareholders have criticized the company’s takeover of Anadarko, including activist investor Carl Icahn who filed a lawsuit against Occidental last week over the transaction.

RELATED: Carl Icahn Sues Occidental Petroleum Over ‘Misguided’ Anadarko Deal

Occidental’s offer for Anadarko is comprised of 78% cash and 22% stock. Including the assumption of debt, the total value of the bid is roughly $57 billion.

Largely believed to be key to the takeover battle is Anadarko’s nearly 600,000 gross-acre position in the Permian’s Delaware Basin. The portfolio of Anadarko—one of the world’s largest independent E&P companies—also includes deepwater projects offshore Africa and in the U.S. Gulf of Mexico plus a position in Colorado’s Denver-Julesburg Basin.

Occidental has already agreed to sell Anadarko’s Africa assets to French energy giant Total SA for $8.8 billion. The Total transaction has also recently came under fire from Algeria’s energy minister who said he would black the acquisition of Anadarko’s Algeria assets in late May.

RELATED: Total To Hold Talks With Algeria Over Anadarko Assets

On June 4, Occidental said the waiting period for the company’s Anadarko acquisition required under the Hart-Scott-Rodino Antitrust Improvements Act was terminated early by the FTC.

The Anadarko takeover deal remains subject to other customary closing conditions, including approval from Anadarko’s stockholders. The companies expect to close the transaction in the second half of the year.

Emily Patsy can be reached at