Electronics companies helped spur a record year for American patents, as the U.S. Patent and Trademark Office issued an average of 476 a day in 2006.

Last year,173,772 corporate patents were issued, an all-time record and a 20.8 per cent increase compared to 2005, according to IFI Claims Patent Services, which annually compiles the patent data.

IBM held onto its U.S. patent crown for the 14th year in a row, receiving a record 3,621 patents.

Electronics companies dominated the list of companies awarded patents, with IBM, Samsung, Canon, Matsushita and Hewlett-Packard all receiving more than 2,000 patents each. Prior to 2006, no company other than IBM had ever received 2,000 patents in a single year.

Electronics patents traditionally have a short lifespan, so companies are continually filing for and receiving new ones to keep pace with innovations.

A separate analysis of the data conducted by the Public Patent Foundation earlier this week found software patents made up a growing sector of intellectual property claims.

Thepatent officeawarded 40,964 software patents, an increase of 36 per cent from the previous year.

The Public Patent Foundation is an organization that tries to invalidate patents and lobby for patent reform. It says software patents often cover trivial technologies and stunt innovation.

Thepatent officesaid it received 440,000 applications, examined 332,000 of them in 2006 and allowed only 54 per cent of those examined, a record low clearance rate.