GENEVA (AP) -- Klaus Schwab, the founder of the World Economic Forum, best known for hosting an annual meeting of political, business and other elites in the Swiss Alpine town of Davos, is retiring as chairman more than a half-century after creating the Geneva-based think tank, the forum said Monday.

The forum quoted Schwab, 87, in a statement as saying he was stepping down "with immediate effect."

Former Nestle Chairman and CEO Peter Brabeck-Letmathe was unanimously selected as interim chairman by the forum's board at a special meeting on Sunday, the statement said. A search committee has been set up to choose a permanent successor.

The forum's annual gathering in Davos has for decades served as a global hub where decision-makers, academics, leaders of international organizations, and elite business executives rub shoulders to discuss government policy, global crises and deal-making.

The gathering, typically in January, has hosted a long list of world leaders under Schwab's 55-year tenure, including President Xi Jinping of China, Vladimir Putin of Russia, Donald Trump of the United States, and many more heads of state and government.

"At a time when the world is undergoing rapid transformation, the need for inclusive dialogue to navigate complexity and shape the future has never been more critical," the forum said in the statement, underlining its mission as a "facilitator of progress" that will continue to bring together leaders to exchange ideas and build cooperation.