For the 12th straight year, IBM has topped the list of companies receiving US patents, according to an annual report published Tuesday by a unit of the Dutch information services company WoltersKluwer.

Big Blue was awarded 3277 patents, followed by Japan's Matsushita Electric Industrial Co with 1965 and Canon KK, a unit of Canon, with 1813. In fourth place was Hewlett-Packard Development Co with 1780 and Micron Technology with 1761, according to the report.

For the first time since 1995, however, the total number of issued US patents declined, down 2.7 per cent to 164,402 from the year before, according to the report.

US companies led all industries with 23 of the top slots, followed by Japan-based companies pinning down 16 slots.

In the biotechnology sector, the University of California, ranked number 42 in the top 50 list, led the biotechnology sector with 447 patents. Other biotech contenders included Applera, Germany's Degussa and the US Government Health and Human Services.

The patent data is based on research compiled by IFI Claims Patent Services, based in Wilmington, Delaware. IFI Claims is a unit of Wolters Kluwer Health, a division of the Amsterdam-based WoltersKluwer Group.