BRUSSELS (Reuters) - The European Commission moved on Tuesday to stem aggressive patent lawsuits by smartphone and tablet makers against rivals, ruling that Motorola Mobility had broken EU law by taking such action against Apple.

In a dual ruling, the European Union's anti-trust enforcer said that it had also accepted a pledge by Samsung Electronics not to seek injunctions against rivals if they had signed up to a licensing agreement for smartphones or tablets.

The landmark ruling will help draw a line under a long-running feud between smartphone makers and a slew of legal action against rivals by manufacturers who claimed they had copied their designs.

No fine will be imposed on Google Inc's Motorola. Case law on the point was unclear.

The Commission ruled nonetheless that it was abusive for Motorola to seek an injunction against Apple in Germany on the basis of a "standard-essential" patent it had committed to license. Apple had agreed to buy a license and pay royalties.

It ordered Motorola to resolve its dispute with Apple through arbitration, without legal action.

"The so-called smartphone patent wars should not occur at the expense of consumers," said Joaquin Almunia, the European commissioner in charge of antitrust enforcement.

"While patent holders should be fairly remunerated for the use of their intellectual property, implementers of such standards should also get access to standardized technology on fair, reasonable and non-discriminatory terms."

The patent wars between tech companies, which also include Microsoft, Nokia and smaller rivals, underscore the fierce battle for market share in the lucrative mobile phone industry.

The world's top smartphone makers, Samsung and Apple, are suing each other in more than 10 countries.