BERLIN (AP) _ German authorities have promised to share information with U.S. law enforcers as they probe possible corporate spying by Volkswagen against General Motors Corp.

Police and prosecutors swept through VW's Wolfsburg headquarters on Thursday, seeking evidence against VW's cost-cutting whiz Jose Ignacio Lopez de Arriortua, once one of GM's highest ranking officials.

Seven other locations, including homes of VW employees, also were searched. Investigators were also looking into VW's computers after the newsmagazine Der Spiegel reported some of the allegedly stolen data was stored there.

Prosecutors in Darmstadt are investigating GM's allegations that Lopez took company secrets with him when he defected to VW in March. Lopez denies the claims, which could result in criminal charges of industrial espionage.

The Justice Department in Washington is looking into the claims of theft of GM documents.

Darmstadt prosecutor's spokesman Georg Nauth said that his office was ready to share information with U.S. investigators if that would help their probe. ''We will support the investigation with all the means at our disposal and contribute to clarifying the situation as rapidly and comprehensively as possible,'' VW said in a statement.

The search is yet another setback for the huge VW concern, which has long been one of the main symbols of German industry. VW posted a loss of about $953 million for the first half of the year.

PS-Report, a news service specializing in the German auto industry, quoted Darmstadt prosecutor Georg Balz as saying the allegations against Lopez are ''not unfounded'' but that the case is extremely complex.

German criminal investigations can drag on for months, especially in complicated cases. That means it could be a long time before prosecutors what to do with Lopez, a tough Spaniard hired to restore VW to profitability.