Steve Ballmer decamps Microsoft board

Microsoft veteran Steve Ballmer will step down from the company's board of directors after 14 years of service to focus on pro basketball.

Steve Ballmer.

Ballmer's decision to step down as a director marks a milestone in Microsoft's history -- for the first time someone other than Bill Gates or Steve Ballmer is running the company.

He joined Microsoft in 1980, hired by founder Bill Gates as the company's first business manager. Ballmer held a range of positions at Microsoft until he was named chief executive officer in 2000 as Gates retired.

During his tenure as chief executive, Ballmer was criticised for being slow to embrace opportunities in the rapidly growing mobile and cloud markets, allowing Apple and Google to overtake Microsoft.

In a letter to his successor as chief executive of Microsoft, Satya Nadella, Ballmer said that he had become very busy as the new owner of the Los Angeles Clippers team after leaving the company six months ago.

Ballmer said that the North American Basketball Association season and teaching will make for a hectic time for him, and therefore, he will depart from the board immediately.

"In the mobile-first, cloud-first world, software development is a key skill, but success requires moving to monetization through enterprise subscriptions, hardware gross margins, and advertising revenues." - Steve Ballmer said in his letter to Satya Nadella.

Nadella accepted his resignation, thanking Ballmer for the boldness and passion he had brought to Microsoft.

Ballmer is the largest individual shareholder in Microsoft and said he will continue to remain so "for the foreseeable future."

The 58-year old Harvard maths and economics graduate is estimated to be worth over US$20 billion (A$21.5 billion).