Sep. 21--In the most detailed revelation yet of Intel's alleged efforts to monopolize the microprocessor market, European regulators on Monday disclosed previously confidential notes from computer company executives that suggest Intel heavily pressured them not to buy chips from its competitor, Advanced Micro Devices.

The European Commission, which fined Intel $1.45 billion in May for anti-competitive practices, said the computer-company documents reveal how Santa Clara-based Intel promised the companies rebates if they avoided using chips from AMD of Sunnyvale, "as well as how Intel sought to conceal its practices."

It cited comments from a Hewlett-Packard executive's 2004 internal e-mail warning that "you can NOT use the commercial AMD line. The risk is too high."

Palo Alto's HP was among a half dozen computer makers or retailers that the commission said was intimidated by demands from Intel, which controls 80 percent of the world market for x86 microprocessors, the brainy chips that execute high-speed instructions in computers and servers.

"Between November 2002 and May 2005, Intel payments to HP were conditioned on HP selling AMD-based business desktops only to small and medium enterprises ... and on HP postponing the launch of its first AMD-based business desktop in Europe by six months," the commission said.

As a condition of rebates, Intel demanded that HP buy at least 95 percent of its microprocessors from Intel, the commission

said.

The arrangement was not one HP was eager to disclose. In another memo cited by the European body, an HP executive wrote, "PLEASE DO NOT communicate to the regions, your team members or AMD that we are constrained to 5 percent AMD by pursuing the Intel agreement."

The allegations are contained in the commission's 518-page decision against Intel, which was edited to remove confidential company information and the names of executives quoted, as well as a commission press release detailing some of the internal computer company notes.

HP spokesman John Allen said his company responded to the commission's request for information "in a factual, forthright manner," but that "it is HP's policy not to publicly comment on pending legal matters."

Intel, which has appealed the European ruling, denied wrongdoing.