UK-based BTG has sued Microsoft and Apple Computer for allegedly infringing a patent which covers web-enabled software update technologies, the company says.

BTG has filed the lawsuit in the US Federal Court in the Northern District of California in conjunction with New York-based Teleshuttle and Teleshuttle Technologies, the holders of the patent which BTG says is being infringed.

BTG holds the worldwide licensing rights to the patent.

The lawsuit charges Microsoft and Apple with infringement of US patent number 6,557,054, alleging that Microsoft's and Apple's operating systems, as well as Microsoft Office products, incorporate the patented technologies.

The lawsuit asks for unspecified damages for past infringing activity and an injunction against future use of the technology.

BTG says it filed the lawsuit because Microsoft and Apple were causing "delay in entering into licensing agreements with BTG on commercially reasonable terms".