A committee organized to welcome the world to Pittsburgh for the September G-20 economic summit has received a donation from a foundation that has, in the past, given millions of dollars to anti-immigration organizations including two listed as hate groups.

The Colcom Foundation, founded by Cordelia Scaife May, a now-deceased heir to the Mellon fortune, has been one of the major contributors to a web of groups founded by John Tanton, a Petoskey, Mich., ophthalmologist who has long been at the forefront of efforts to restrict immigration into the United States.

During Ms. May's lifetime, the foundation also underwrote the work of Samuel Francis, a self-described "white nationalist" who edited a newsletter for the Council of Conservative Citizens, a group that has advocated racial separation. Mr. Francis also was a regular speaker at conferences sponsored by American Renaissance, an annual gathering of academics who theorize on racially based differences in intelligence, contending that black people have lower intelligence than whites and Asians.

A Colcom spokesman yesterday, responding to a reporter's e-mail requesting comment on the group's history of grants, did not directly address questions surrounding Mr. Tanton and Mr. Francis.

But John Rohe, Colcom vice president for philanthropy, said the foundation opposes racism and is not anti-immigrant.

"Let's agree up front that acts of racism and race-based decisions should not be tolerated. Never. Period," Mr. Rohe said. "Colcom Foundation supports efforts to educate the American people about immigration policy and its role in the 21st Century. The Foundation is pro-immigrant and believes the nation's welcoming spirit should continue. The question is not whether the U.S. should allow immigration, but rather how much."

Heidi Beirich, head of research for the Southern Poverty Law Center who has done extensive studies of the immigration control movement, called the list of Colcom recipients "quite a lineup of haters."

"It's beyond ironic that Colcom would be giving money to welcome the world to Pittsburgh, while simultaneously having bankrolled notorious white supremacists like Sam Francis and some of the most racist anti-immigrant groups in the country," Ms. Beirich said.

Officials of the Pittsburgh G-20 Partnership, which is overseeing hospitality for visiting delegates and press at the September economic summit, said they were unaware of Colcom's history of giving to immigration restriction groups. Dennis Yablonsky, executive director of the Allegheny Conference on Community Development, one of the principal organizers of the committee, declined to say how much Colcom or any other foundations donated to the partnership.

Word of Colcom's giving history surprised Allegheny County Executive Dan Onorato, who said he remembered the group for a grant that helped complete the remaining nine miles of the Great Allegheny Passage bicycling trail.

Records show that Colcom has also given millions to a variety of other undertakings, including a statue honoring the late Fred Rogers, the American Red Cross and a $1 million grant in 2007 to the National Aviary.