Sony Ericsson has filed a U.S. patent application for a mobile device with video game features, but said on Monday it is not poised to launch a phone based on its PlayStation Portable (PSP) video game brand.

Sony Ericsson filed a patent application dated May 31 with the U.S. Patent & Trademark Office related to a mobile device with gaming functionality that originated from employees in Japan.

The fourth-biggest cell phone maker did not rule out the development of a device combining its phone technology with Sony's portable video game technology, but said it was not ready to announce any products.

Sony's comments came after newspaper and blog reports speculating that Sony Ericsson would launch a phone based on Sony's popular PSP handheld gaming device.

Sony Ericsson has succeeded in selling music phones and camera phones that capitalize on its well-known Walkman music player brand and its Cyber-Shot digital camera brand.

But the company aid the company did not release these products until it was at a point where it felt customers did not have to compromise on either the phone or the media capability.

There has been no word from Sony's gaming division about a new PSP, much less one with a phone built in, a U.S., according to Reuters.

The announcement comes two weeks before Apple launches sales of its widely anticipated music-playing iPhone in the United States on June 29.