FORMER Microsoft chief executive Steve Ballmer has left the company's board in order to spend more time on his newly-acquired Los Angeles Clippers basketball team, but said he plans to hang on to his four per cent stake in the software giant.

The 58-year-old Mr Ballmer paid $2 billion to take control of the basketball team earlier this month.

He had spent 34 years at Microsoft, having joined it when it was still a small start-up business based in the suburbs of Seattle.