British Telecommunications says it invented the hyperlink technology used on the Internet and that it has a U.S. patent to prove it.

As a result, it is asking American ISPs (Internet service providers) to pay for the privilege of using the technology, BT said yesterday.

"BT has about 15,000 patents worldwide and in a routine check, we discovered we have the patent for the hyperlink," said BT spokesman Simon Gordon.

Specifically, BT says that it has what it calls the Hidden Page patent, which was filed in the U.S. in 1976 and granted in 1989, giving the company the intellectual property rights to the hyperlink technology, Gordon said.

Hyperlinks connect text, images, and other data on the Internet in such a way as to allow a user to click on a highlighted object on a Web page in order to bring up an associated item contained elsewhere on the Web.

Similar patents were filed in other countries, but have since expired. The U.S. patent does not expire until October 2006, Gordon said.

Gordon declined say how much BT expects to charge for licensing fees or how much the company expects to make from its claims on the patent, but agreed it would be a sizable sum.

According to BT, the technology for its hyperlink patent originated from general research done on text-based information systems, specifically a system called Prestel, that was done by an employee of the General Post Office (GPO) in the 1970s. The GPO was split into BT and the Post Office in 1981 and the employee has since retired, according to BT.

Lawyers in the U.K. versed in intellectual property rights have questioned the wisdom in BT's patent claim. "It is not going to make them very popular and if BT wants to expand into the United States, I wonder how milking this patent is going to effect that," said Ben Goodger, a technology and intellectual property expert for the law firm Willoughby & Partners.

"It could very well be that legally it all stacks up, I'm sure BT has thoroughly checked into the legalities of the patent. If it's true and the patent holds up in court, then they really have got the whole of the U.S. over a barrel," Goodger said.