BT is claiming it invented the hyperlink technology used on the Internet, and it’s asking US ISPs to pay for the technology, it said on Wednesday.

BT claims it has a US patent on the technology.

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

It’s ours BT says it has what it calls the Hidden Page patent, filed in the US in 1976 and granted in 1989, which gives BT the intellectual property rights to the hyperlink technology, Gordon said. Hyperlinks connect text, images, and other data on the Internet. They 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 US patent does not expire until October 2006, according to BT. Gordon said: "Early this year, we wrote to 17 top US ISPs asking to be reimbursed for the use of the technology. We've heard back from the majority of those companies, all saying that they need to review the matter and get back to us."

After the money BT has hired UK-based technology-development and -licensing company Scipher to broker licensing agreements with US ISPs. BT said that it would not pursue patent claims with individual users, as it would "not be practical".

Gordon declined to 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 sizeable sum. He added: "We realized the value of this one patent three years ago, and have been reviewing with our legal experts which was the best way forward."

There were around two billion pages on the Web as of January this year, according to the Internet Society Organization (ISOC), a US-based trade association. Depending on whether a page is privately run or commercial run, typical pages have between one and three hyperlinks, or between 50 to 100 hyperlinks, according to ISOC.

’70s throw-back BT claims the technology for its hyperlink patent originated from general research done on text-based information systems, specifically a system called Prestel, that was conducted 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.

World Wide Web Consortium (W3C) spokesman Ian Jacobs said: "We have not read the patent and do not know what it claims. Obviously, we've been getting a lot of telephone calls about this, so what we are doing is directing people to our homepage where we have a little history of the World Wide Web and hyperlink posted."

Jacobs said: "People at W3C, out of sheer interest, will look at the patent I am sure, but we'll decide in the future if it is worth making any sort of formal comment on."

Is it wise? Lawyers in the UK have questioned the wisdom of BT's claim. Ben Goodger, a technology- and intellectual-property expert for the UK law firm Willoughby & Partners, said: "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."

However it seems unlikely, if a company such as America Online refused to pay hyperlink licensing fees, that BT would seek to enforce its patent through the US courts and request that the offending sites be shut down. Goodger said: "Imagine if they shut down the AOL portal?"

Goodger said: "It may be that BT will be clever enough to just ask enough in licensing fees, and leverage their patent just enough, to get companies to pay in an attempt to make the problem go away. It's a bit like cyber squatters in that case."