UK telecoms goliath BT is suing games developer and publisher Valve, alleging the Steam service infringes multiple patents.

In a complaint [PDF] filed with the Delaware district court, BT accused Valve of ripping off four technologies it has patented related to the operation of cloud services (in this case, Steam). This is the same BT that once upon a time tried to sue American ISPs for using hyperlinks.

In its latest wave of kamikaze litigation, the UK broadband provider reckons Valve has infringed...

US Patent 6,578,079 : Communications node for providing network-based information service.

: Communications node for providing network-based information service. US Patent 6,334,142 : Method for automatic and periodic requests for messages to an email server from the client.

: Method for automatic and periodic requests for messages to an email server from the client. US Patent 6,694,375 : Communications network and method having accessible directory of user profile data.

: Communications network and method having accessible directory of user profile data. US Patent 7,167,142: Multi-user display system.

According to BT, all four of the patents have been borrowed on to construct major components of Steam's streaming games service and the social networking community that has been built around it.

"Valve has derived and will continue to derive substantial value from these products and services, which incorporate the patented technologies," BT argues in the filing, submitted to the courts last month.

According to the British comms house, its lawyers have been trying for years to speak with Valve and strike a deal to pay a licensing fee for the patents. BT claims that Valve has not so much been declining its efforts for talks, as it has been ignoring them altogether.

"Despite BT's repeated attempts to reach an amicable resolution with Valve, and BT's numerous requests that Valve stop infringing the Patents-In-Suit, Valve has continued to infringe willfully and wantonly," the complaint reads.

"BT brings this action to recover the just compensation it is owed for Valve's past infringement, and to prevent Valve from continuing to benefit from the patented inventions in the future without authorization or compensation to BT."

Should the two sides not be able to resolve the matter with a licensing agreement in the meantime, BT is asking the court for a jury trial to determine damages from back royalties, as well as attorneys' fees and other administrative costs.

Valve, which did not respond to a request for comment on the case, has until September 19 to file its response with the court. ®