Claims against Porsche

and Volkswagen filed with a German court have reached 1.8 billion euros ($2.3 billion), the court said, as compensation demands pile up for allegedly holding back crucial information from shareholders.

A spokeswoman for the court in the city of Braunschweig also said on Friday that an additional lawsuit had been filed against the two German car companies, without saying how much in damages was sought as part of that case.

A Porsche spokesman said the company had not received an additional case and declined to comment further. Volkswagen would not comment.

Massive demands for damages have been brought by enraged investors who took wrong-way bets on a decline in VW shares in 2008. They claim they were misled by the sportscar maker about how many shares in VW it held at the time, leading to a short squeeze that turbo-charged VW shares.

When Porsche revealed it controlled 74.1 percent of VW's voting stock in October 2008, shares of Volkswagen topped 1,000 euros apiece, having more than quadrupled within just days.

Incredulous investors who had bet on an imminent end to the surge saw VW briefly become the world's biggest company by market value.

But Porsche's attempt to take over its much larger peer eventually failed and backfired, as VW now controls the maker of the iconic 911 sportscar.

Volkswagen was forced late last year to postpone a planned merger with Porsche Holding, the legal entity used in Porsche's takeover attempt of VW, in part due to the legal onslaught brought by investment funds.

Last week, a group of funds filed a suit against Porsche with a Stuttgart court, seeking almost 2 billion euros in compensation for losses incurred in the short squeeze.

The cases in Germany follow similar suits filed by investors in the U.S., which have so far failed.

($1 = 0.7817 euros)

(Reporting by Jan Schwartz; Writing by Ludwig Burger; Editing by Helen Massy-Beresford)