France’s antitrust authority on Tuesday fined Sanofi 40.6 million euros ($52.6 million) for a “smear campaign” designed to limit sales of generic versions of Plavix. The ruling on the drug, which last year generated global sales of nearly 2.1 billion euros ($2.7 billion), follows a complaint by Teva.

The competition authority claimed that Sanofi’s sales force cast doubt on the efficacy of generic versions of Plavix in conversations with doctors and pharmacists in 2009 and 2010. The drugmaker also urged doctors to write on prescriptions that the generic version was not substitutable for the branded product, and pushed for use of its own generic version rather than those from other companies.

According to the competition regulator, France’s national health system paid 625 million euros ($810 million) for the use of Plavix in 2008, the most of any medicine. Sanofi said that it disagrees with the ruling and is “reviewing all the points to prepare an appeal before the Paris appeals court.”