Social networking web site Facebook is allegedly suing German look-alike social network StudiVZ in an intellectual property case after it failed to acquire it, reported The International Herald Tribune on Thursday.

The German site, launched a year and a half after its American counterpart, shows striking similarities with the world’s second largest social-networking web site.

Just like Facebook, it mostly targets college students and allows users to connect with classmates, friends of friends etc.

In its federal court complaint, Facebook said the German site was a knockoff “built by copying the look, feel, and features of Facebook.”

StudiVZ’s interface is very similar to that of the Palo Alto, California-based company, except for the choice of color – a dark red instead of Facebook’s famous blue.

These similarities in look and content concerned Facebook, which stated in its complaint that “because StudiVZ looks like Facebook, and incorporates similar features and functionality to Facebook, users will incorrectly believe that StudiVZ is associated with Facebook.”

According to the IHT report Facebook first tried to acquire the copycat rival, which would have avoided this legal imbroglio and increased Facebook’s grip on the German market.

Facebook, which launched its German-language portal five months ago, is lagging behind the German site, which counts ten times more users in Germany.

But the acquisition talks were shattered when the Holtzbrinck Gruppe, which acquired StudiVZ for $134 million in January 2007, judged Facebook’s offer too low. They reportedly wanted several times the amount they had paid earlier last year.

According to the IHT, it is unclear where the case, filed in U.S. District Court in San Francisco, will be tried because of international borders.

The copying lawsuit is not the first for the American social network founded in 2004. Facebook recently settled a case opened a year ago years ago by the creators of ConnectU, who accused the company’s founder Mark Zuckerberg to have stolen their business plan.

Facebook closed the lawsuit by acquiring ConnectU for a combination of cash and stock.