By BBC News Online internet reporter 
Mark 
            Ward 
            UK firm BT is claiming ownership of a key part of the internet. 
            
The telecommunications giant says it came up with idea for 
            hyperlinks that turn separate pages of information into an 
            interconnected whole. 
            
Clicking on a hyperlink whisks you from one webpage to another. 
            
BT says a patent filed in the US in 1976 and granted in 1989 
            gives it ownership of hyperlink technology 
            
Link licence 
            
Now, it is asking US internet service providers to pay to use 
            what it considers to be its intellectual property. 
            
If the claim is successful, BT stands to make millions from the 
            licence agreements. 
            
            
                
                    
                        
                        Berners-Lee: The scientist is 
                        usually credited as the inventor of the world wide 
                        web
    | 
 Currently, there are around 1.5bn pages on 
            the web. Each one has, on average, 52 links on it. 
            BT filed patents on the hyperlink idea in other countries but 
            these claims have now expired. 
            
However, the US patent runs out in 2006. 
            
Ben Goodger, a technology and intellectual property expert from 
            law firm Willoughby and Partners, said BT would be unwise to try and 
            enforce its claim. 
            
"The commercial damage and unpopularity which BT would bring 
            on its head if it tried to enforce this patent would be 
            incalculable," he said. 
            
Mr Goodger said in the 1980s Unisys tried to enforce its claim to 
            a technology which was widely used to compress image files. 
            
He said Unisys was vilified for its action at the time especially 
            when it started charging $5000 per licence. 
            
Now over 2000 companies have paid Unisys for a licence to use the 
            compression system known as the LZW algorithm. 
            
            
Post Office pioneer 
            
BT rediscovered the Hidden Page patent three years ago during a 
            routine trawl of its 15,000 patents. 
            
The growing popularity of the internet has spurred it to 
            capitalise on the patent. 
            
"It is only now that the world wide web has become 
            commercially significant," said a BT spokesman. 
            
He added that BT has spent the time preparing its licensing 
            programme for companies that want to use hyperlinks. 
            
"It takes a long time to prepare a licensing programme of 
            this magnitude," said the spokesman. 
            
Now, it has employed intellectual property experts Scipher, 
            formerly the Thorn-EMI research lab, to pursue those using 
            hyperlinks. 
            
So far, BT and Scipher have sent letters to lots of US internet 
            service providers - it is not planning to ask individual users to 
            pay to use the web. 
            
BT is now talking to the ISPs about licensing agreements. It 
            declined to divulge how much a licence to use the hyperlink 
            technology would cost. 
            
The original patent was filed after work done on text based 
            information systems such as Prestel by the General Post Office 
            (GPO). 
            
The GPO was split into BT and the Post Office in 1981. 
            
Just as hyperlinks now let people navigate around the internet, 
            this early work helped users retrieve information from computers 
            they were indirectly connected to. 
            
Despite BT's claims to the contrary, Tim Berners-Lee is usually 
            credited with inventing the global hypertext system that became the 
            world wide web. 
            
Mr Berners-Lee says that in creating the WWW he drew on the work 
            of computing pioneer Ted Nelson - who is widely regarded as the 
            father of 
hypertext.