Giant computer chipmaker Intel is being sued by Advanced Micro Devices (AMD) for anti-competitive practices.
Intel's computer chips are used in the majority of personal computers
The lawsuit covers x86 microprocessors, used to run PC operating systems, including Microsoft Windows, Solaris and Linux systems.
AMD said its lawsuit alleges that Intel has coerced customers away from dealing with AMD, and is based on evidence obtained from 38 companies.
Intel has declined to comment on the lawsuit filed by AMD.
AMD filed its case in a federal court in the US state of Delaware on Monday.
"Everywhere in the world, customers deserve freedom of choice and the benefits of innovation, and these are being stolen away in the microprocessor," said AMD president and chief executive Hector Ruiz.
Intel dominates global sales of x86 microprocessors with 80% of sales by volume and 90% by revenue, according to AMD.
A report on first quarter 2005 microprocessor sales by independent research firm Mercury found Intel had 82% of the PC processor market and AMD had 17%, with VIA and Transmeta mopping up the rest, The Register website reported.
AMD alleges that Intel has used its position to force major customers, such as NEC, Acer and Fujitsu, into exclusive deals or to cap customer purchases of AMD chips.
Its lawsuit quotes then-Compaq chief executive Michael Capellas saying that Intel once withheld delivery of certain chips as punishment for the level of Compaq's business with AMD.
"Saying 'he had a gun to his head', Mr Capellas told AMD he had to stop buying," AMD's statement said.
In another example, AMD quotes Gateway executives who said Intel had "beaten them into 'guacamole'" in retaliation for doing business with AMD.
"We are trying to bust open Intel's chokehold over the computer companies and get the right to compete freely and fairly for every processor they buy," said Charles Diamond, attorney for AMD.