The chief executive of Nokia, the world mobile phone leader, gave credit to new competitors from the computer world on Wednesday, but said his company was set to respond to all challengers.

Nokia President and CEO Olli-Pekka Kallasvuo said emerging rivals Apple Inc, Google Inc, Research in Motion Ltd and Microsoft Corp have helped to accelerate interest in using the Internet on mobile phones.

"Suddenly you have the mightiest companies in the world there as your competitors. That is a little mind-boggling," Kallasvuo said in an on-stage interview at the Churchill Club, a speakers' forum for Silicon Valley civic leaders.

Nokia sells more than 400 million phones a year and counts a 40 percent share of the conventional global mobile phone market, where it competes with Samsung, Motorola, LG Electronics and Sony Ericsson, among others.

He said he was impressed by the strategy of Research in Motion (RIM), maker of the BlackBerry e-mail phone popular with business professionals, to sell not just devices themselves but whole solutions for managing corporate e-mail securely.

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