NEW YORK (AFP) - Anadarko Petroleum said Thursday it will pay US$5.1 billion (S6.4 billion) to settle environmental claims against Kerr-McGee, an oil company it acquired in 2006.

The settlement follows a December US court ruling that said Anadarko owed as much as US$14.5 billion to address Kerr-McGee's environmental liabilities prior to the acquisition.

Anadarko said the settlement removed doubts that have depressed the value of its stock.

The dispute concerns claims that Kerr-McGee, which also had a chemicals business, left waste sites around the United States tainted with uranium contamination, thorium and other toxins that pollute land and water.

In the December ruling, US bankruptcy judge Allan Gropper said Kerr-McGee executed a fraudulent reorganization of its assets ahead of the US$18 billion Anadarko deal to off-load the waste sites to Tronox, which fell into bankruptcy in 2009 and before emerging in 2011.

The settlement is with a group of Tronox plaintiffs and the US government.

The trust's beneficiaries include more than a dozen states and the Navajo Nation.

The settlement "eliminates the uncertainty this dispute has created, and the proceeds will fund the remediation and cleanup of the legacy environmental liabilities and tort claims," said Anadarko chief executive Al Walker.

"Investor focus can now return to the tremendous value embedded in Anadarko's asset base."