PHILADELPHIA Archbishop Charles J. Chaput, Gov. Corbett, and Mayor Nutter gave a breakfast briefing Tuesday to about 170 business, civic, and cultural leaders about the fund-raising needs for the possible visit of Pope Francis to Philadelphia next year.

The trio led a delegation to Rome last month to urge the pope to attend the World Meeting of Families, a triennial event scheduled for Sept. 22 to 27, 2015. Popes usually attend these meetings, which can draw a million people to the host city for the pontiff's outdoor Mass.

The last time a pope visited Philadelphia was in 1979, when John Paul II drew more than a million people to the Benjamin Franklin Parkway to attend Mass. Francis has emerged as a popular figure, and a visit to Philadelphia could generate similar or greater attention.

An event of this magnitude will cost tens of millions of dollars, and the World Meeting of Families, as a nonprofit, is designated to collect donations to help cover the costs.

There is no specific fund-raising goal yet, but "the budgeting process for the World Meeting of Families is taking into account the 2000 Republican National Convention, Pope Benedict XVI's 2008 visit to New York, and the 2012 World Meeting in Milan," said Meg Kane of Brian Communications, which is handling public relations for the nonprofit.

To help organize the 2000 convention, which Philadelphia hosted, nearly 500 business and government entities raised $66 million.

Not all of the attendees at the breakfast, at the Union League, were potential donors. There were representatives from the Free Library, the Philadelphia Zoo, and the Philadelphia Orchestra, Kane said.

Besides Philadelphia, Francis could include a trip to New York City to address the United Nations.

The Vatican does not officially announce papal visits until several months in advance.