In a it labeled "rumor," the gadget blog Gizmodo quoted an unnamed source as saying Apple "is choosing to remove the hype factor strategically" by holding the keynote without Jobs, whose "health is rapidly declining." Gizmodo said the source had been correct in the past, though only about Apple products and not about Jobs. Apple did not comment for the Gizmodo post and did not immediately respond to IDG News Service requests for comment.

Apple's Nasdaq stock (AAPL), which had closed at $86.61 on Monday, fell as low as $84.72, a drop of about 2 percent. But shares ended the day at $86.29, down just $0.32, or 0.37 percent.

Apple announced on Dec. 16 that Phil Schiller, senior vice president of worldwide product marketing, would deliver the keynote at Macworld Expo in San Francisco on Jan. 6. For many years since he returned to Apple in 1997, Jobs has given that speech and used it as a launch platform for important products, including the iPhone in 2007 and the MacBook Air in 2008.

At the same time, Apple said it would stop exhibiting at Macworld Expo after the January event. The company said trade shows had become a minor part of its marketing strategy.

Concerns have been raised about Jobs's health since his appearance at Apple's Worldwide Developer Conference in June, when some observers said he appeared gaunt. Jobs said in 2004 that he had undergone surgery for pancreatic cancer. On Oct. 3, Apple shares fell more than 10 percent after a report that Jobs had suffered a major heart attack. The stock recovered after Apple said the report, from a "citizen journalist" on an unfiltered section of CNN's Web site, wasn't true.