If you think Apple Computer's Steve Jobs invented the technology behind the Apple iPod, don't bet your 60GB, 15,000-song model on it.

According to the U.S. Patent and Trademark Office, patent applications that cover much of the technology associated with the iPod were submitted by Microsoft, which has been on a patents tear recently filing thousands of patents.

If the patents hold up on appeal, Apple could be accountable for royalties on the spectacularly successful iPod. Jobs and others associated with Apple filed for patents covering the technology in October, 2002, but that application was rejected by the patent office last month. AppleInsider.com reported the rejection this week.

Apple won't take the matter lying down. "Apple invented and publicly released the iPod interface before the Microsoft patent application cited by the (patent) examiner was filed," said an Apple spokesperson in a statement. Apple also noted that the firm has received other patents for technology relating to the iPod and in addition has other patents pending on the iPod.

The documents in the Patent Office do not mention the iPod by name. The documents describe a "portable, pocked-sized multimedia asset player" that can manipulate MP3 music files.

Microsoft's claim appears to center on the work of John C. Platt, a senior researcher in the Knowledge Tools Group at Microsoft Research. According to media reports, on behalf of Microsoft, Platt applied for the patent in May of 2002 some five months before the Apple filing. Platt's application was rejected in December 2004, but he amended it in April of this year and Microsoft's pending patent was subsequently approved.

According to a citation on "Platt's home page, he and other colleagues at Microsoft developed a paper in the 2001-2002 timeframe discussing AutoDJ, "a system for automatically generating music playlists based on one or more seed songs selected by a user."

Apple's iPod dominates the MP3 player market. The NPD Group has reported that Apple has shipped nearly 22 million iPods. Predictions that Apple's strength in the MP3 market would slip haven't borne out, and Apple accounts for about 75 percent of MP3 players sold in the U.S.

So far, Microsoft hasn't been able to dent the Apple iPod dominance, although the software giant has said it is working on music playing devices that it plans to introduce later this year.