The commission, the European Union's top antitrust regulator, has spent years investigating Intel's tactics to determine whether it acted unfairly to preserve its dominance over AMD.
"I can confirm the statement of objections has been sent," said Ton Van Lierop, a spokesman for the European Commission. Intel had no immediate comment.
The two companies make all the central processing unit chips at the heart of the world's 1 billion personal computers and servers.
The formal charges are contained in a statement of objections.
On July 19,
AMD gained market share against Intel in 2005 and most of 2006, but suffered a downturn later last year when Intel rolled out powerful new processors and cut prices on older models.
AMD's market share at the end of 2006 was 25 percent of unit shipments for x86 processors that act as the brains for almost all the world's personal computers.
But by the end of March 2007, AMD had slipped to less than 19 percent, according to market research firm Mercury Research.
AMD's stock has fallen this year while Intel's has risen.
Intel has had some past government challenges. It settled charges with the United States Federal Trade Commission in 1999 and the FTC dropped an additional investigation about the firm's marketing practices in 2000.
"We have not been informed by the EC of the issuance of a statement of objections concerning Intel," AMD said in a statement. "On the basis of an initial press report, we await the EC's public description of its apparent decision to charge Intel with illegal monopoly practices that harm consumers--as well as Intel's response," the company said.
CNET News.com's Tom Krazit contributed to this report.