Intellectual Ventures has filed a lawsuit in Delaware against Motorola Mobility after failing to reach a licensing agreement with the phone maker, AllThingsD reported on Thursday. The suit names six different patents. “Intellectual Ventures has successfully signed licensing agreements with many of the top handset manufacturers in the world, and has been in discussions with Motorola Mobility for some time,” chief litigation counsel Melissa Finocchio said. Intellectual Ventures’ licensees include HTC, Samsung and Research In Motion, which signed a licensing agreement with the company earlier this year. “We have a responsibility to our current customers and our investors to defend our intellectual property rights against companies such as Motorola Mobility who use them without a license,” Finocchio added.