Google is reportedly courting an antitrust charge by the US Federal Trade Commission because of its insistence that Microsoft and Apple pay gouging royalties for Motorola Mobility's standards-essential patents.

The Wall Street Journal said Friday that Google "is weighing whether to settle a potential claim" by the agency.

The FTC has reportedly threatened to bring a case against the company under Section 5 of the FTC Act, which governs unfair or deceptive business practices, for using the patents as a weapon against its rivals. They are supposed to be licensed on FRAND terms.

When Microsoft and Apple refused to pay 2.25% of the selling price of their widgets for a license Motorola sued seeking injunctions that would ban the sale of their products. A US court has ordered Motorola not to enforce the injunctions it got in Germany.

The paper says Google has argued "that competitors that own FRAND patents, including Apple, have acted improperly by suing Motorola and others rather than licensing the patents fairly" and that by settling "it effectively would be disarmed while competitors continue their abuse."

That argument doesn't seem viable and apparently "the FTC believes it has evidence that some people at Google admitted to colleagues that the company's conduct with such patents was wrong."

It's unclear what it would take to settle the possible complaint, maybe an agreement by Google to modify its behavior.

When the Justice Department waved Google's $12.5 billion acquisition of Motorola Mobility through, it said that Google had made some very wishy-washy commitments about using Motorola's patents fairly unlike Apple and Microsoft when they bought FRAND patents from Nortel Networks and Novell.

The FRAND issue is separate from the investigation the FTC has been conducting for more than a year into Google's search practices.