A firm based in Seattle specializing in caller identification technology has sued Apple Inc. (Nasdaq: AAPL) for patent infringement, alleging that the tech giant is illegally using its inventions on iPhones.

Cequint Inc. petitioned a federal court in Wilmington, Del., Monday to stop Apple from using its caller ID system, which identifies and displays the names of callers not stored in the contact list of a mobile phone. The petition also seeks unspecified damages from the iPhone maker for infringing on two patents related to its technology.

Apple has yet to comment on the complaint.

Cequint was founded in 2004 while the first iPhone was launched in 2007. Cequint is now owned by Transaction Network Services, which acquired it in 2010.

Cequint's lawsuit adds to the various lawsuits filed against Apple in some countries. The iPhone maker also has pending countersuits to the complainants, including Samsung of South Korea.