U.S. software company Versata filed a complaint with European Union antitrust regulators accusing German software company SAP AG of shutting it out of the market.

The move could lead to the European Commission, the EU's antitrust watchdog, opening an investigation into the case. Privately-held Versata, which won a U.S. court case against SAP in August last year for patent violations, filed its complaint with the Commission on Tuesday, Versata's lawyer Thomas Vinje said.

He said SAP, the world's leading provider of business software, had refused to share interoperability information and had cloned Versata's Pricer pricing software which it then bundled with its product, resulting in fewer choices for consumers.

SAP uses tactics that the European Commission found illegal in the 2004 Microsoft case, Vinje said.

SAP declined comment.

Microsoft ended its decade-long battle with the EU watchdog in December last year by promising to give consumers better access to rival Internet browsers in Windows. Its antitrust infringements cost the company 1.68 billion euros ($2.1 billion) in regulatory fines.

Vinje said the Commission should take action to open the software market.

Versata asks at a minimum that the Commission require SAP provide interoperability information and that it unbundle its own pricing configuration software from its dominant enterprise resource planning software, he said.

In the patent case, the U.S. court ordered SAP to pay Versata $139 million.

SAP counts McDonald's, Pepsi, Audi, Apple and GE among its clients. It competes with U.S. software companies Oracle, IBM and Microsoft.

(Editing by David Holmes)

($1=.8194 Euro)