“We have raised three incredible children and built a foundation that works all over the world to enable all people to lead healthy, productive lives,” they said in a statement. 

“We ask for space and privacy for our family as we begin to navigate this new life.” 

Bill Gates was formerly the world's richest person and his fortune is estimated at well over USD100 billion. 

How the couple end up settling their estate and any impact on the foundation will be closely watched, especially after another high-profile Seattle-area billionaire couple recently ended their marriage. 

Amazon CEO Jeff Bezos and MacKenzie Bezos finalised their divorce in 2019. MacKenzie Scott has since remarried and now focuses on her own philanthropy after receiving a 4% stake in Amazon, worth more than USD 36 billion. 

The Gateses were married in 1994 in Hawaii. They met after she began working at Microsoft as a product manager in 1987. 

In her 2019 memoir, "The Moment of Lift", Melinda Gates wrote about her childhood, life and private struggles as the wife of a public icon and stay-at-home mom with three kids. 

She won Bill Gates'' heart after meeting at a work dinner, sharing a mutual love of puzzles and beating him at a math game. 

The sprawling Seattle-based Bill and Melinda Gates Foundation is the most influential private foundation in the world, with an endowment worth nearly USD50 billion. It has focused on global health and development and US education issues since incorporating in 2000. 

As the public face of the foundation's COVID-19 grants and advocacy work, Bill Gates has come under fire for being a staunch supporter of intellectual property rights for vaccine makers. While the tech icon says protecting the shots'' recipes will ensure incentives for research and development, critics claim that mentality hampers supply in favor of drug company profits. 

Last year, Bill Gates said he was stepping down from Microsoft's board to focus on philanthropy. 

He was Microsoft's CEO until 2000 and since then has gradually scaled back his involvement in the company he started with Paul Allen in 1975. He transitioned out of a day-to-day role in Microsoft in 2008 and served as chairman of the board until 2014.