Intel, the world's biggest semiconductor maker, was yesterday accused by its closest microprocessor rival of a global plot to force computer makers and retailers not to buy its competitor's products.

Advanced Micro Devices (AMD) said it had filed an antitrust complaint in a Delaware court detailing how Intel had unlawfully maintained a monopoly and identifying 38 companies it said had been victims of coercion.

The move follows a complaint by AMD to the European Commission alleging anti-competitive practices and a ruling by Japan's Fair Trade Commission earlier this year. Intel employs 3,600 at its manufacturing facility in Leixlip.

The ruling said Intel had violated antitrust laws by offering rebates to five Japanese PC makers in exchange for limiting purchases of AMD chips.

The US Federal Trade Commission has investigated Intel twice, but closed both cases.

AMD has a long history of litigation against its much larger rival and, with Intel processors featuring in four out of every five PCs sold, has waged a public relations war to try to raise its profile and brand among computer buyers.

The latest complaint quotes executives of computer maker Gateway claiming Intel had "beaten them into guacamole" for having limited dealings with AMD.

It cites Michael Capellas, then chief executive of Compaq, telling AMD in 2000 "he had a gun to his head" when Intel withheld delivery of critical server chips because of the volume of business he had given to AMD.

Tom Beermann, Intel spokesman, said the company disagreed with the complaints and believed in competing fairly.

The case is expected to be brought before the court in 2006.

AMD shares were up 2.8 per cent in midday trading in New York at $17.11 (€14.17), while shares of its rival stood 0.7 per cent higher at $26.05.