European news sources are reporting that European Union officials conducted surprise dawn raids Wednesday at the offices of a number of pharmaceutical companies, including Pfizer, GlaxoSmithKline, Sanofi-Aventis, AstraZeneca, Merck Sharp & Dohme, Johnson & Johnson’s Belgian unit, Wyeth, and Novartis’ Sandoz division.

What’s the beef? Reports say the EU is looking for evidence of patent abuse. Here’s how the AP described it:

[EU antitrust chief Neelie Kroes] will examine whether companies were deliberately preventing new firms from entering the market by abusing patent rights and launching “vexatious litigation” to ward off potential rivals.

It said the probe was partly triggered by its 2005 case against AstraZeneca in which the company was fined 60 million euros ($73 million) for filing misleading information to patent offices to delay generic versions of its ulcer drug Losec for most of the 1990s.

Fewer new medicines are reaching the market, regulators said, one sign that competition may not be working. Only 28 new types of drugs were launched from 2000 to 2004, far fewer than the 40 that hit the market from 1995 to 1999.

“The Commission wants to investigate the reasons for this and in particular whether any agreements restricting competition or unilateral abuses of dominant position are connected to it,” the EU said.

The EU is expected to issue a report on the matter later this year.