“I think that if you look at the market today, volumes speak volumes. In the last year we shipped over 20m phones,” he told the Financial Times, “I'd say, mostly, it's game on – we are all out there. We are leading the pack on volume. I'd say Apple's got some advantages on image, but we're in the early stages.”

Mr Ballmer told the annual Mobile World Congress industry trade show in Barcelona yesterday: “We need to take our Windows Mobile business to another level.”

While Mr Ballmer did not mention rivals by name, the latest announcements appear designed to ensure that mobile phones powered by Windows Mobile are able to compete more effectively against competitors, including Apple's iPhone and the new handsets powered by Google's Android operating system.