Finnish mobile phone giant Nokia Friday announced that its chief executive Olli-Pekka Kallasvuo would be replaced by Microsoft's Stephen Elop Sep 21.

Elop, a Canadian, currently heads the computer giant's business division. He previously worked with Juniper Networks, Adobe Systems Inc and Macromedia Inc.

'The time is right to accelerate the company's renewal; to bring in new executive leadership with different skills and strengths in order to drive company success,' Nokia board chairman Jorma Ollila.

Kallasvuo succeeded Ollila as chief executive in 2006. In recent years, Nokia has faced increasing competition, especially in the high-end market with the likes of Apple's iPhone.

Nokia said Kallasvuo would also leave the board of Nokia but would stay on as non-executive board chairman of Nokia Siemens Networks, the joint venture between Nokia and Germany's Siemens.