CHICAGO — Intel Corp. has been hit with a $500 million lawsuit charging infringement of an obscure RISC-architecture patent developed by a once high-flying chip startup. Intel officials said the suit is without merit and they plan to contest it.

The patent at issue was awarded in November 1996 to International Meta Systems Inc., which was then developing the Meta6000 CPU, a Pentium Pro-class clone microprocessor intended to fit into a Pentium Socket-7 connector. Specifically, the patent is number 5,574,927, "RISC architecture computer configured for emulation of the instruction set of a target computer."

Rights to the patent were subsequently sold to a Chicago-based company called TechSearch, which has filed the patent suit against Intel in U.S. District Court for the Northern District of Illinois. TechSearch is charging that Intel's Pentium II and Pentium Pro microprocessors infringe on its technique for emulating the instruction set of a target computer on a RISC architecture.

"I don't think there's any question we have a case," said Raymond Niro, lead attorney for TechSearch. "The issue is whether Intel wants to be rational or to fight, in which case we'll let a jury decide."

Niro said he has contacted Intel. "We're in the process of talking with Intel's attorneys about possible royalties," he said. "This is what we told Intel: We think a reasonable royalty range is 1 percent to 3 percent of net sales, or between $60 million and $180 million a year for the life of the patent. If we were to go to trial, damages could exceed $500 million."

Niro said he's seeking a cash payment to settle in advance of trial. "Our client is looking for a one-time resolution of all issues," he said.

Intel doesn't think TechSearch has a case. "We are going to vigorously defend ourselves," an Intel spokesman said. "This suit is without merit."

At least one patent expert agrees. "It's an annoyance lawsuit," said Rich Belgard, a microprocessor patent expert in Saratoga, Calif. "People buy patents and they sue the big guys. I don't think Intel will roll over. I think they'll fight it and win."

"The hardware claims [in the patent] both have 'means plus function' language, which means you have to interpret them according to what's in the patent," Belgard explained. "On that basis, I think the suit is going to fail."

The next legal step in the case is a status hearing scheduled for August 20 in Chicago.

The original source of the patent, International Meta Systems, has fallen on tough times. According to a form filed in June with the U.S. Securities and Exchange Commission, the company is currently undergoing reorganization proceedings in Austin, Texas.

The company is proposing to sell the majority of its assets, including its semiconductor intellectual property and integrated circuit process technology, to a newly created corporation called IPIQ. At press time, International Meta Systems officials hadn't return calls seeking comment.

Separately, Intel is currently in an ongoing legal battle over patent rights with Intergraph Corp. in U.S. District Court in Alabama. Last year, Intel and Digital Equipment Corp. traded patent lawsuits and then settled their litigation.