Steve Ballmer, former Microsoft Chief Executive who recently purchased the Los Angeles Clippers from shamed owner Donald Sterling, has announced he is leaving Microsoft's board so he can focus on the basketball franchise. Ballmer will retain his 4% stake in Microsoft. Ballmer said, "I see a combination of the Clippers, civic contribution, teaching and studying taking a lot of time. The fall will be hectic between teaching a new class and the start of the NBA season so my departure from the board is effective immediately." in a letter to Microsoft CEO Satya Nadella that was made public by Microsoft.