The French Competition Authority fined drugmaker Sanofi €40.6 million ($52.7 million) on Tuesday for "disparaging" generic competition to its Plavix blood thinner.

The decision on Tuesday follows a complaint filed in 2010 by Teva Sante, a French unit of Israel-based Teva Pharmaceutical Industries, against Sanofi's communication practices towards health professionals aimed at discouraging the use of generic versions of Plavix.

Sanofi's communication "created a doubt over the quality and the safety of generics, without any proven basis, as nothing could demonstrate that Plavix generics were less safe than (the original drug)," the Competition Authority said in a statement.

Sanofi said in a statement that it disputed the decision and was considering a possible appeal.

"Sanofi never challenged the bio-equivalence of Plavix generics," it said. "Sanofi never specifically targeted the Teva Sante generic or other Plavix generic versions."

Earlier this month Sanofi reported lower-than-expected first-quarter earnings as sales were hit by generic competition, austerity measures in Europe and the depreciation of several currencies.

The expiry of Sanofi's patent on Plavix, once the world's second-best selling prescription drug, was expected to slice around €800 million off earnings in the first half of 2013, Sanofi had said.