SAN FRANCISCO — Intel Corp. may have to change the way it conducts business globally if European regulators prove allegations that the company abused its position as the world's biggest chipmaker.

SAN FRANCISCO — Intel Corp. may have to change the way it conducts business globally if European regulators prove allegations that the company abused its position as the world's biggest chipmaker.

The European Commission on Friday formally accused the Santa Clara, Calif., company of practices that violated antitrust laws, such as offering computer-makers improper discounts and rebates to discourage them from buying microprocessors from Intel's smaller rival, Advanced Micro Devices Inc., or AMD.

The commission said Intel's tactics were "part of a single overall anti-competitive strategy" that hurt consumers.

The charges showed the European Union's growing willingness to challenge American multinational companies that it believed competed unfairly. Intel joined Microsoft Corp. and Apple Inc. as dominant high-tech companies in the commission's sights.

"It's a big deal because ultimately it may lead to reform," said David Balto, former policy director at the Federal Trade Commission. "It may stop Intel from doing a whole bunch of practices that have been cutting AMD off at the kneecaps."

Intel has 10 weeks to file a response with the EU. The company denied the charges in public statements Friday, calling the semiconductor industry "fiercely competitive."

Investors reacted mildly, sending Intel shares down 46 cents, or 2 percent, to $23.54 on a down day for the markets. The news failed to stop AMD's recent stock slide; its shares lost 86 cents, or 6 percent, to $13.87.

With their charges, the European regulators could alter Intel's global practices by threatening huge fines or cease-and-desist orders.

"We Americans are just not used to thinking that what the European Commission does can have a profound effect on us," said Robert H. Lande, a University of Baltimore law professor and director of the American Antitrust Institute, a consumer-focused think-tank in Washington. "But it's a new world, and it can."