Microsoft co-founder Bill Gates says he is stepping down from the company’s board to focus on philanthropic activities.

Mr Gates was Microsoft’s chief executive until 2000 and since then has gradually scaled back his involvement in the company he started with Paul Allen in 1975, who died in 2018.

Mr Gates transitioned out of a day-to-day role in Microsoft in 2008 and served as chairman of the board until 2014.

The billionaire announced on Friday that he is leaving the Microsoft board entirely as well as his seat on the board of Berkshire Hathaway, the conglomerate headed by fellow billionaire Warren Buffett.

“I have made the decision to step down from both of the public boards on which I serve – Microsoft and Berkshire Hathaway – to dedicate more time to philanthropic priorities including global health and development, education, and my increasing engagement in tackling climate change,” Mr Gates said on LinkedIn.

“The leadership at the Berkshire companies and Microsoft has never been stronger, so the time is right to take this step.”

Mr Gates will also remain a technology adviser to Microsoft’s executive leadership.

He said he plans to dedicate more time to the Bill and Melinda Gates Foundation.

In 2018 The Chronicle of Philanthropy named the couple the most generous philanthropists in the US, after they gave US$4.8 billion ($7.4 billion) to their foundation the previous year.

Mr Gates is listed by Forbes as the world’s second richest man after Amazon founder Jeff Bezos, and is worth more than US$100 billion ($160 billion).