The U.S. Justice Department announced Monday that it has reached a $32 million settlement with Mobil subsidiaries of the Exxon-Mobil Corp. over unpaid natural gas royalties. The agreement is the latest chapter in long-running litigation in the U.S. District Court for the Eastern District of Texas.

The lawsuit, U.S. ex rel. Wright v. Chevron USA Inc., et al., was originally filed by Harold Wright in October 1998 as a whistleblower suit under the False Claims Act. The Justice Department, which intervened in the case, alleges that Mobil Natural Gas Inc., Mobil Exploration & Producing U.S. Inc. and their affiliates knowingly underpaid royalties owed on natural gas produced from federal and American Indian leases from 1988 to 1999.