Internet search giant Google has sued BT, saying the British telecoms group has infringed a number of its technologies.
Google claimed that the London-based firm in California violated four of its patents.
According to the BBC, BT had been expecting such action after it launched its own case against Google in 2011.
Google has struck back with claims that BT has infringed a method to allow PCs to use an internet-based telephone system based on a patent originally filed by Fujitsu.
It also said that BT failed to license a system used to let computer servers prioritise data - an IBM invention now owned by the search firm.
According to the report, BT and Google are next set to meet in court in Delaware in July for a mediation hearing about the 2011 case. (ANI)