The suit, filed today in the U.S. District Court of Delaware, claims that Via and its S3 Graphics Inc. subsidiary infringed upon five of Intel's patents in its recently introduced Pentium 4-complaint chip set line, dubbed the P4X266 and P4M266. The P4X266 is a chip set designed for desktop PCs based on the Pentium 4 processor, while the P4M266 is used for mobile applications.

By selling these new chip sets in the market, Via is causing "irreparable harm" to Intel, according to the suit. The Santa Clara, Calif.-based chip giant is seeking unspecified damages from Taipei-based Via. Officials from Via have yet to return phone calls.

Intel's move did not surprise analysts. Via initially unveiled its P4X266 at Taiwan's Computex trade show in Taipei during in early June. But unlike its core logic rivals in Taiwan and elsewhere--including Acer Laboratories, ATI, and Silicon Integrated Systems--Via did not obtain a Pentium 4-based chip set license from Intel.

Via insisted that an older Intel cross-licensing agreement brokered by S3 Graphics--now a Via subsidiary--was applicable to future Intel buses.

At the time, Intel disagreed but the company did not clearly state what action it would take against Via when the product appeared on the market. Recently, Intel chief executive officer Craig Barrett said any company introducing a product compatible with or using Intel's intellectual property should be "very careful" if it doesn't have a license.

The apparent dispute between Via and Intel caused Taiwan's major motherboard makers to publicly say they will not use the P4X266 in products until the issue is resolved (see Aug. 15 story ).

Then, last month, Via accused Intel of trying to stop it from selling chip sets for Pentium 4 processor-based PCs by using "scare tactics" and warning customers that the Taiwan company is infringing upon protected technologies in a recently introduced product (see Aug. 23 story ).

"Intel has made repeated claims both in the media and in discussions with customers that we are not licensed to sell products that are compatible with the Intel Pentium 4," said Richard Brown, director of marketing at Via, at that time. "We disagree with these and other scare tactics that Intel is employing in the PC industry for marketing purposes," he added.

Now, Via finds itself tangled in another legal mess. In fact, the company is no stranger to legal pressure from Intel.

In June of 1999, Intel filed suit against Via over chip set patents involving the Pentium III chip. That case, filed in the U. S. District Court for the Northern District of California, is still pending.

In today's suit, Intel said Via has infringed upon five patents. The first one is U.S. Patent No. 6,145,039, which is entitled "Method and Apparatus for an Improved Interface Between Computer Components," according to the suit.

The second patent involves U.S. Patent No. 6,009,477, which is entitled "Bus Agent Providing Dynamic Pipeline Depth Control." Meanwhile, the third is U.S. Patent No. 5,761,449, entitled "Bus System Providing Dynamic Control of Pipeline Depth for a Multi-Agent Computer."

The next one is U.S. Patent No. 5,615,343 for an invention entitled "Method and Apparatus for Performing Deferred Transactions." And finally, the fifth one is U.S. Patent No. 5,659,689, which is entitled "Method and Apparatus for Transmitting Information on a Wired-Or Bus."