A sign marks the Raytheon offices in Woburn, Massachusetts, U.S. January 25, 2017. REUTERS/Brian Snyder

(Reuters) - Raytheon Co RTN.N on Thursday won the dismissal of a $1 billion whistleblower lawsuit accusing the defense contractor of overbilling the U.S. government on a contract for satellite sensors, nearly 1-1/2 years after a federal appeals court revived the case.

U.S. District Judge Otis Wright in Los Angeles said Steven Mateski, an engineer who worked for Raytheon from 1997 to 2006, failed to adequately allege that the Waltham, Massachusetts-based company submitted a false claim, or that its actions were material to the government’s payment decisions.

A lawyer for Mateski did not immediately respond to requests for comment on the False Claims Act case, which began in 2006. Raytheon did not immediately respond to a similar request.

Mateski had accused Raytheon of mismanaging a subcontract to develop a weather sensor for the National Polar-Orbiting Operational Environmental Satellite System (NPOESS), on which Northrop Grumman Corp NOC.N held the main contract.

In March 2016, the 9th U.S. Circuit Court of Appeals said Mateski’s claims went beyond known problems in developing the NPOESS, which suffered from delays and cost overruns, and overturned Wright’s dismissal of the case three years earlier.

But in Thursday’s decision, Wright said Mateski’s fraud allegations remained too general, and his “barebones” allegations regarding materiality also required dismissal.

Wright pointed to Raytheon’s counterargument that any alleged misrepresentations were not material to the government’s payment decisions, given how the government kept paying its invoices long after being alerted to alleged suspect claims.

Mateski had amended his complaint five times, and Wright said he would not permit a sixth amended complaint.

False Claims Act cases let whistleblowers pursue claims on behalf of the government and share in recoveries. The United States decided in 2012 not to help Mateski pursue his case.