2nd UPDATE: EU Raids Drugmakers On Antitrust Concerns

The European Commission Tuesday said it has conducted surprise antitrust inspections of several pharmaceutical firms.

The commission, the European Union's executive arm, didn't name any of the companies involved. French drugmaker Sanofi-Aventis (SAN.FR) said it was one of the companies raided.

While the commission declined to comment on the nature of the suspected violations, it has been investigating the steps brand-name drug-makers take to prevent generic competitors from bringing their products to market. E.U. antitrust commissioner Neelie Kroes said in July that deals between big pharmaceutical companies and generic firms raise concerns that the industries are agreeing to avoid competing with each other.

"There is something rotten" with the deals, she said.

The U.S. Justice Department is also investigating whether these deals violate antitrust laws.

The inspections announced Tuesday are among the first steps in a commission antitrust probe, which can often take years to complete.

Merck KGaA (MRK), Bayer AG (BAYN.XE), GlaxoSmithKline PLC (GSK), UCB SA (UCB.BT) and Solvay SA (SOLB.BT) weren't among the firms raided, spokespeople for the companies said Tuesday.

-By Matthew Dalton, Dow Jones Newswires; [phone]; [e-mail]

(Marietta Cauchi in London contributed to this article.)