BT sues over hyperlink claim

BT has taken a large US ISP to court over its patent for hyperlink technology.

The lawsuit, filed against Prodigy Communications Wednesday in a New York federal court, follows BT's claim in June that it owns the intellectual property rights to hyperlinks. BT says the patent, discovered in a routine trawl through its own patents three years ago, also covers a basic technology necessary for connecting computer users to the Internet.

The telco aims to require all ISPs who use hyperlinks -- a fundamental Web technology -- to pay BT a licence fee. BT declined to say what rate it plans to charge, but critics say the patent enforcement will make BT immensely unpopular no matter what the fee. It is also unclear whether BT's claim will be sustainable given the existence of previous hypertext-like inventions.

BT contacted Prodigy and 16 other ISPs, including America Online, in June asking them to buy a hyperlink licence. The lawsuit says Prodigy "has wilfully infringed" BT's patent.

A BT spokesman said the company does not rule out other lawsuits against ISPs. The suit is to "demonstrate the effectiveness of the patent in general", the spokesman said.

The patent application was made in 1976 by Post Office researchers working on information services called Prestel and Viewdata. BT was at the time part of the Post Office. The US Patent Office granted patent number 4873662 in 1989.

Prodigy was founded in 1984 and has a subscriber base of about 2.5 million. It provides a DSL service as well as other ISP services.