UIQ Technology uses Symbian OS and licenses its UIQ user interface and application development platform to mobile phone vendors worldwide.
Following completion of the acquisition, UIQ Technology will operate as a separate business subsidiary of Sony Ericsson under its current management team.
The communications firm said that UIQ on Symbian OS will continue to be openly available, and licensed on equal terms to all its licensees.
Sony Ericsson is already a licensee of UIQ Technology, and said it has been working closely with the company on UIQ 3.0, which is included in Sony Ericsson's P990 smartphone, M600 messaging phone and W950 Walkman phone.
Mats Lindoff, chief technology officer at Sony Ericsson, praised UIQ's technology, which supports push email, internet browsing, end user personalisation and enhanced mobile music applications.
"We welcome this decision by Sony Ericsson to purchase UIQ Technology as it will give us the additional investment needed to compete in the rapidly expanding software market for advanced phones," said Johan Sandberg, chief executive at UIQ Technology.
Sony Ericsson expects the transaction to be completed over the next few months, pending regulatory approval and closing conditions.
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