BT, which earlier in the year said it had discovered that it owns the US patent for the invention of the hyperlink technology used on the Internet, has sued one of the largest ISPs in the US for copyright infringement. The telco filed the suit in federal court in White Plains, NY, last week. BT declined to give details about any damages the telco is seeking from Prodigy. Representatives from Prodigy could not immediately be reached for comment. After discovering in a routine check that it owned the patent for the hyperlink, BT wrote to 17 US ISPs, including Prodigy, asking them to pay for the privilege of using the technology through licensing agreements. The suit filed against Prodigy, which claims to be the largest consumer DSL ISP in the United States, is the first suit BT has filed to protect its hyperlink patent, according to a BT representative.