The Swiss branches of Eli Lilly and Co., Pfizer and Bayer were fined a total of $5.7 million by regulators for fixing the price of erectile dysfunction drugs.

The Swiss Competition Commission said the prices of Pfizer’s Viagra, Indianapolis-based Lilly’s Cialis and Bayer’s Levitra were fixed in the form of public price recommendations. It didn’t say how much each company was fined, and a commission spokesman declined to provide the information.

The three companies rejected the allegation. “We are surprised by the decision, and we believe the public price recommendation for Cialis was in full compliance with Swiss competition law,” said Petra Streit, a Lilly spokeswoman.

Bayer was examining how it could challenge the fine, according to a statement.

“We’re of the opinion that this decision will not survive a court examination,” Pfizer added.