It is not clear whether Intel has been unable to produce enough of the 1.13-GHz chips or whether there was a technical glitch. Intel executives were not immediately available to comment.
The move comes as rival Advanced Micro Devices today began shipping a 1.1-GHz Athlon processor.
IBM, which had been selling systems with the Intel chips, is telling telephone customers that computers with the 1.13-GHz chip are no longer available.
"We're not taking new orders at this time," an IBM representative said. "We do not expect to take orders again until the October time frame."
A Dell representative confirmed the company has stopped selling machines with Intel's speediest chip.
"It's off the Web site," the representative said, without providing details about the problem or saying when Dell expects to resume sales.
Intel announced the 1.13-GHz chip on July 31, saying it was shipping in limited quantities. Dell and IBM had offered systems using the chip.
Analyst Nathan Brookwood of Insight 64 said last week that Intel appears to be having problems shipping large volumes of its fastest chips
"They are by all reports hard to find, even the (1)-GHz ones," Brookwood said.
Supply issues have been a persistent problem for Intel during the past year, as the company has experienced more demand than it had built manufacturing capacity for.