BRUSSELS (Reuters) - U.S. heart valve maker Edwards Lifesciences has been hit with an EU antitrust complaint by Indian rival Meril including for allegedly anti-competitive practices related to patents, a move that could bolster EU regulators' scrutiny of Edwards.

Regulators on both sides of the Atlantic have recently taken a tougher line against the pharmaceutical industry to ensure that smaller innovative companies can compete with bigger rivals and that prices for drugs and products remain affordable.

Meril has filed a complaint with the European Commission, the company told Reuters. The two companies have for years sparred over heart valve patents in various courts around the world.

Edwards, a global leader known for its transcatheter aortic valve replacement (TAVR) device in heart surgery, was raided by the EU antitrust watchdog last year on concerns that it may have abused its market power in breach of the bloc's antitrust rules.

Meril's complaint singled out Edwards' global unilateral pro-innovation (anti-copycat) policy which it alleged aims to prevent doctors from engaging with anyone Edwards labels as a patent copier.

The Indian company also took issue with Edwards' patent practices which it said include evergreening - when firms extend patents on their products by making slight changes to a compound - and patent thickets, which refer to a pharma company's practice of seeking multiple patents for minor variations on a single invention.

Edwards rejected Meril's allegations, saying it has fairly secured injunctions against Meril's Myval system in 7 countries and the Unified Patent Court for the infringement of its SAPIEN valve and accessory patents.

It said it asserted its patents against Meril because "it substantially copied Edwards' technology, rather than competing fairly and designing their own technologies". 

"Intellectual property rights are essential to protect and incentivise innovations like those in Edwards' therapies, which save and transform the lives of millions of patients across the world," Edwards said in an email to Reuters.

"We have an unwavering commitment to healthy, fair competition and we believe that Meril's complaint to the European Commission is designed to circumvent competition and the decisions of national courts," it said.

Edwards in a February regulatory filing said the Commission is investigating certain business practices including its anti-copycat policy and patent practices.

Meril's complaint said Edwards has launched a disparagement campaign with incomplete information on its intellectual property status and ongoing patent lawsuits.

The Commission declined to immediately comment. EU antitrust breaches can cost companies fines of as much as 10% of their global turnover.

(Reporting by Foo Yun Chee; Editing by Kirsten Donovan)

By Foo Yun Chee