Co-founder Bill Gates is stepping down from the board of Microsoft, the company announced

Bill Gates is leaving the board of Microsoft, the company announced Friday.

The Microsoft co-founder, 64, is to dedicate more of his time to his charity, the Bill & Melinda Gates Foundation

He has been spending more time on his philanthropic work since 2008, when he transitioned out of his day-to-day role at Microsoft.

Now the world's second-richest person worth $103.6 billion, Gates founded Microsoft in 1975 with Paul Allen, who died in 2018.

Gates remained as Microsoft CEO until 2000 when he was succeeded by Steve Ballmer. He stepped down as director of the board in 2014.

Microsoft did not announce a replacement on the board to Gates but said that it will now consist of 12 members.

'It's been a tremendous honor and privilege to have worked with and learned from Bill over the years,' said current Microsoft CEO Satya Nadella, who took over the role in 2014.

Melinda Gates and Bill Gates. He will be dedicating more time to their foundation

Microsoft co-founder Paul Allen who Gates founded the company with 45 years ago

'Bill founded our company with a belief in the democratizing force of software and a passion to solve society's most pressing challenges. And Microsoft and the world are better for it.

'The board has benefited from Bill's leadership and vision. And Microsoft will continue to benefit from Bill's ongoing technical passion and advice to drive our products and services forward.

'I am grateful for Bill's friendship and look forward to continuing to work alongside him to realize our mission to empower every person and every organization on the planet to achieve more.'

Gates remains one of Microsoft's main shareholders owning 1.36 percent in shares.

It is one of the most highly valued company's in the world, valued at $1.21 trillion.

'On behalf of our shareholders and the Board, I want to express my deep appreciation to Bill for all his contributions to Microsoft. As a member of the Board, he challenged us to think big and then think even bigger. He leaves an enduring legacy of curiosity and insight that serves as an inspiration for us all,' added John W. Thompson, Microsoft independent board chair.

Gates is said to be stepping down to dedicate more time to his philanthropic work and his foundation but will remain as Technology Advisor to CEO Nadella.

Current Microsoft Corporation Chief Executive Officer Satya Nadella gave his thanks to Gates

His charity work focuses on global health, development, education and tackling climate change.

Warren Buffett's Berkshire Hathaway Inc also announced on Friday that Gates is retiring from the conglomerate's board of directors, and is expected to be replaced by Kenneth Chenault, who spent 17 years as chief executive of American Express Co.

The change was disclosed in Berkshire's annual proxy filing, ahead of its scheduled May 2 annual meeting.

Gates has served on Berkshire's board since 2004.

Chenault, 68, led American Express from January 2001 to February 2018, and became one of the most prominent black CEOs in corporate America.

Berkshire is the largest shareholder in American Express, ending 2019 with an 18.7 percent stake in the travel and financial services company.

It said its governance committee reviewed 23 possible candidates for board seats in 2019, and Chenault emerged as 'a standout and unanimous choice'.

The proxy filing also detailed compensation for top Berkshire executives in 2019.

Buffett, 89, was awarded $374,773, including his usual $100,000 salary plus $274,773 for personal and home security services.

Vice Chairmen Greg Abel, 57, and Ajit Jain, 68, who respectively oversee Berkshire's non-insurance and insurance operations, were each awarded $19 million, up from $18 million in 2018.

Buffett sets compensation for Abel and Jain, who many investors view as top candidates to eventually succeed him as chief executive. Berkshire does not grant stock options.

As Gates invests more and more time to the Bill & Melinda Gates Foundation, the charity has begun funding a new home-testing kit for coronavirus that is expected to be ready for distribution in the greater Seattle area in the coming weeks.

The test will allow people experiencing symptoms of coronavirus to swab their noses and then send the samples to a lab for an analysis.

The foundation is dedicated to eradicating illness in developing countries.

Gates has warned that the coronavirus is beginning to behave like a 'once-in-a-century' pathogen with the potential to kill more people than the 66,000 Americans who died in the 1957 influenza pandemic.

'The data so far suggest that the virus has a case fatality risk around 1 per cent,' Gates wrote at the end of February.

'This rate would make it many times more severe than typical seasonal influenza, putting it somewhere between the 1957 influenza pandemic (0.6 per cent) and the 1918 influenza pandemic (2 per cent).'