The European Commission started Tuesday investigations on whether Motorola Mobility Inc., now a subsidiary of Google, has violated relevant EU anti-trust laws by hindering competitors from gaining access to certain patents.

The case was conducted at request of Apple and Microsoft, both competitors of Motorola Mobility, as they complained to the Commission that Motorola Mobility had been using injunctions against their key products like iPhone and Xbox.

The European Commission will investigate whether Motorola has failed to honor its irrevocable commitments made to standard setting organizations, and also assess the allegation by both Apple and Microsoft that Motorola offered unfair licensing conditions for its standard-essential patents in breach of EU laws.

Joaquin Almunia, Vice-President of the European Commission and Commissioner responsible for competition, said last week in Washington that he was considering whether to open the investigation.

"I am considering whether we need to investigate these complaints formally to help bring more clarity into this area of competition control," he said.

"The holders of standard-essential patents have considerable market power. This market power can be used to harm competition ... I don't need to tell you that this is unacceptable, and I am determined to use antitrust enforcement to prevent such hold-up by patent holders," Almulnia said.

The European Commission also issued a warning towards Google when it approved the 12.5 billion U.S. dollar acquisition in February.