A federal judge has dismissed a large portion of Advanced Micro Devices' anti-trust lawsuit against Intel, saying that US law does not cover many of AMD's claims.

The decision by judge Joseph Farnan of the US District Court in Delaware follows several quarters in which AMD, the world's number two maker of chips used in personal computers, had taken business from its larger rival.

Sunnyvale, California-based AMD accused Intel in its 2005 lawsuit of building up a dominant market share for some microprocessors by engaging in anticompetitive conduct, including forcing major customers not to buy AMD products.

Intel, based in Santa Clara, California, countered that AMD was seeking damages mostly for lost sales of German-made, Asian-assembled microprocessors to foreign customers.

It called such damages "a foreign anti-trust injury (if it is one at all) for which the US courts cannot provide relief," according to a 2 May court filing.

Lacked jurisdiction

Farnan accepted this argument, concluding that he lacked jurisdiction over AMD's claims based on conduct and harm that took place outside the US.

"AMD has not demonstrated that the alleged foreign conduct of Intel has direct, substantial and foreseeable effects in the US which gives rise to its claim," Farnan wrote in an 18-page opinion.

At best, he said AMD's allegations described activity that might have had "ripple effects" in the US, but not enough to give rise to an anti-trust claim.

"We're pleased that the judge appears to have agreed with our view of the legal issues and the argument we made," Intel spokesman Chuck Mulloy said. He declined further comment pending a Wednesday conference with the judge.

AMD spokesman Mike Silverman said: "Notwithstanding the judge's ruling today, Intel cannot escape anti-trust scrutiny for its conduct wherever in the world it occurs. As this US litigation is joined by global anti-trust investigations, it is clear that Intel cannot escape the consequences of its illegal monopoly abuses."