The settlement would end a drawn-out legal battle between Unocal and the FTC over the energy company's rights to a patent for reformulated gasoline.

The federal agency's commissioners have yet to approve the companies' proposal, according to Joe Simons, an attorney for Paul Weiss Rifkind Wharton & Garrison, and former director of the Federal Trade Commission's Bureau of Competition.

"I don't know if the commission will approve it or not.