Sony Ericsson is selling half of its smartphone software unit UIQ to U.S. rival Motorola, Sony Ericsson's president, Miles Flint, told reporters in London on Monday.

Sony Ericsson P1i More Photos View Specs

Sony Ericsson W960i More Photos View Specs

Motorola RIZR Z8 More Photos View Specs

The Swedish-Japanese handset maker acquired UIQ from British mobile software maker Symbian last year for an undisclosed sum, and would not comment on the price of the latest deal.

Motorola will acquire a 50% interest in UI Holdings BV, the parent company of UIQ Technology AB, which is currently wholly owned by Sony Ericsson. Under the agreement, Motorola and Sony Ericsson will work together and jointly invest in the development of the UIQ open user interface platform.

UIQ Technology licenses the UIQ open user interface and development platform to mobile phone vendors around the world.

Sony Ericsson and Motorola each have been UIQ licensees for many years and have launched several successful Symbian/UIQ based products including, the Sony Ericsson P1i smartphone, the new Sony Ericsson W960i Walkman phone and the Motorola RIZR Z8. UIQ, offered the industry's first touch-screen interface back in 2002, and now supports both QWERTY and classic numerical keyboard configurations as well as finger touch data input.