F.T.C. Says Rambus Illegally Monopolized Memory Chip Markets

A federal agency ruled yesterday that the computer technology developer Rambus unlawfully monopolized markets for four memory chip technologies. The company’s shares declined as much as 30 percent.

The ruling from the Federal Trade Commission puts at risk tens of millions of dollars in royalties that Rambus, which has no manufacturing facilities, earns from licensing its technology to other chip makers.

“It’s definitely a big setback for the company,” said Daniel Amir, an analyst at W. R. Hambrecht. “It’s all downside in a way. When you’re losing a case against the government, you’re dealing with broad implications.”

In a statement, the agency said that Rambus, “through a course of deceptive conduct,” was able to distort industry standards for a type of memory chip known as dynamic random access memory, or DRAM.

That allowed the company to “engage in an anti-competitive ‘holdup’ of the computer memory industry,” the agency said.

The remedy sought by the agency would bar Rambus from enforcing existing licensing agreements, along with some patents. The agency said it ordered more briefings to determine the remedy.

Rambus shares fell $4.33, or 25.5 percent, to close at $12.65, after falling as low as $11.80.

Rambus, based in Los Altos, Calif., said it thought it could continue with its licensing activity and existing lawsuits, including patent cases against Micron Technology and Hynix Semiconductor.

A senior legal adviser at Rambus, John Danforth, said the company would probably appeal the ruling.

The agency brought antitrust charges against Rambus in June 2002, and a trial took place in 2003.

In 2004, an administrative law judge dismissed charges that Rambus illegally monopolized crucial chip technologies. But employees at the agency asked its five commissioners to overrule the decision.

For years, Rambus has been seeking royalties from memory chip makers on patented technology it asserts is used in DRAM chips that are used in almost all computers.

Last month, Rambus said it would accept a damage award of $134 million in the Hynix case, in which a jury found that Hynix knowingly violated Rambus patents.

“This definitely puts some stains, I would say, on Rambus’s case,” Mr. Amir said. “It probably pushes out any potential settlements. If I’m Hynix, I would say I probably have some basis for an appeal now.”

In 1990, Rambus filed for a patent for a new type of memory called RDRAM. The company then became a member of an industry group called Jedec that was trying to agree on standards for another memory technology, called SDRAM.

The F.T.C. cited a half-dozen instances in the mid-1990’s in which it said Rambus had secretly applied to amend a patent to cover technologies Jedec was considering for SDRAM.

Rambus has maintained it never did anything to violate Jedec’s rules.