Google said today that it had filed suit against British Telecom in the United States and the United Kingdom claiming patent infringement, just over a year after BT alleged that Google infringed on its intellectual property.
CNET reviewed the U.S. lawsuit, which alleges that BT infringes on four Google patents relating to the transfer of files within a network. The patents at stake in the U.S. suit were acquired by Google from companies including IBM and Fujitsu.
The new filing comes in the wake of BT's December 2011 lawsuit against Google, which alleged that the Mountain View company infringed on six of its U.S. patents relating to navigation, communication, and information storage.
The U.K. lawsuit is not yet available because BT has not been formally served.
"We have always seen litigation as a last resort, and we work hard to avoid lawsuits," Google said in a statement. "But BT has brought several meritless patent claims against Google and our customers -- and they've also been arming patent trolls. When faced with these kind of actions, we will defend ourselves."
BT declined to comment on Google's suit, saying it does not comment on pending litigation.
Google's accusation that BT is "arming patent trolls" relates to the practice known as "patent privateering," in which a company transfers intellectual property to a "nonpracticing entity" with a requirement that the entity file suit against companies that infringe on the patent. BT sometimes takes a cut of the money generated from licensing and litigation of the transferred patents, and at least one such nonpracticing entity, Suffolk Technologies, has filed suit against Google.