Bill Gates is stepping down from the board of Microsoft Corp., the company he co-founded in 1975 and built into the world's largest software maker, to devote more time to philanthropy.

Gates, 64, has been scaling back his involvement in the company for more than a decade. Most recently he had been serving as an adviser to current Chief Executive Officer Satya Nadella on technology areas including productivity, health software and artificial intelligence, and he will continue to do so."Microsoft will always be an important part of my life's work and I will continue to be engaged with Satya and the technical leadership to help shape the vision and achieve the company's ambitious goals," Gates wrote in a blog post Friday. "I feel more optimistic than ever about the progress the company is making and how it can continue to benefit the world."

Gates hasn't been active in a day-to-day role since 2008, Microsoft said in a statement. That is when he switched to devoting the majority of his time to the Bill & Melinda Gates Foundation. Gates now wants to spend more time working on global health, education and tackling climate change, according to the statement. He served as CEO of Microsoft until 2000, the same year his foundation was started, and was chairman of the company until February 2014.