In a quiet meeting closed to the news media and the public, Bill Gates, David Rockefeller Sr., Oprah Winfrey and other leading philanthropists met in New York this month to discuss ways to promote efforts to solve growing social problems in America and abroad.

Together, the philanthropists in the room have committed a total of more than $72.5 billion to charitable causes since 1996, according to Chronicle of Philanthropy tallies.

The unusual event was held May 5 at Rockefeller University and was organized by the Bill & Melinda Gates Foundation. Among the high-profile participants were Ted Turner, Warren E. Buffett, George Soros and New York City Mayor Michael R. Bloomberg. (All of those philanthropists have appeared at one time on The Chronicle’s ranking of America’s most-generous donors.)

Several of the people at the meeting confirmed their involvement, but declined to tell The Chronicle about what was discussed or why they gathered almost in secret.

According to a person familiar with the meeting, the wealthy philanthropists gathered to trade ideas about how to raise the level of philanthropy in the world.

According to IrishCentral.com, a Web site in New York that writes about Irish Americans and which first disclosed some of the details about the gathering, each philanthropist was given 15 minutes to talk about “how they saw the future global economic climate, the future priorities for philanthropy, and what they felt the elite group should do.”

Other people who attended included Eli Broad, a real-estate investor, Julian H. Robertson, Jr., a hedge-fund manager, and Patty Stonesifer, former chief executive of the Gates foundation.