Bill Gates is still one of the world's richest men.

Microsoft co-founder and one of the world’s richest men, Bill Gates, has entered into an agreement for his private investment entity, Cascade Investment, to increase its stake in Four Seasons Hotels and Resorts from the existing 47.5% to a controlling interest of 71.25%.

The USD$2.21 billion move increases Cascade’s stake in the luxury hotel operator by 23.75% and builds on its initial investment made back in 1997. Overall, the combined shareholding values Four Seasons Hotels and Resorts as an USD$10 billion enterprise. The sale is expected to close in January next year, pending regulatory approvals.

The additional 23.75% stake acquired by Cascade Investment will come from Kingdom Holding Company, a state-owned entity of the Kingdom of Saudi Arabia. The group is a highly active investor in luxury hotels and operators along with various other market leading brands around the world including the Accor Group, Uber, Twitter, Citigroup, The Plaza Hotel in New York City and The Savoy Hotel in London.

A Full Harbour Room at Four Seasons Sydney.

Four Seasons CEO, John Davison, said the transaction marks a pivotal point in the evolution of the company and will provide the resources to accelerate growth and expand its strategic goals.

“As we mark our 60th anniversary and look back on the profound impact that Four Seasons has had on luxury hospitality we also look forward with tremendous excitement and confidence in the future of the industry,” Davison said.

“The unwavering support and partnership of our shareholders has and continues to be critical as we capitalize on growing opportunities to serve luxury consumers worldwide.”

The remaining 5% in Four Seasons Hotels and Resorts will continue to be owned by the company’s Founder and Chairman, Isadore Sharp. The Four Seasons managed portfolio now consists of 121 hotels and resorts and 46 residential properties in 47 countries, with a pipeline of 50 projects.