Kroc was known in recent years as a major donor to organizations working to promote world peace, including namesake think tanks at the University of Notre Dame and the University of San Diego. She inherited the San Diego Padres after her husband died in 1984 and sold the baseball club in 1990 to a group led by Los Angeles television producer Tom Werner.

Kroc died at her home in Rancho Santa Fe, a wealthy enclave north of San Diego, several months after being diagnosed with glioblastoma, a form of brain cancer, said Dick Starmann, her spokesman.

Kroc ranked No. 121 on Forbes magazine's latest list of the nation's wealthiest people, with an estimated net worth of $1.7 billion. Her donations created Notre Dame's Joan B. Kroc Institute for International Peace Studies in 1986 and the University of San Diego's Joan B. Kroc Institute for Peace and Justice in 2001. She was also a major benefactor of the Carter Center of Emory University in Atlanta.

Kroc contributed $12 million to establish the Notre Dame center after hearing the Rev. Theodore M. Hesburgh, then president of the university, warn about the arms race at a San Diego talk in 1985, said Scott Appleby, the center's director.

"She walked up to him after the talk and said, 'I'm going to help you,'" said Appleby. "She was a passionate champion of peace and justice and she was single-minded in her dedication to eliminating the threat of nuclear weapons and all forms of deadly violence."

Kroc had told friends and acquaintances recently that she was deeply concerned about the turn in world events since the Sept. 11 terror attacks.

"She was very opposed to the war in Iraq and war in general," Appleby said. "She really thought the war in Iraq was a misadventure from the beginning."

The University of San Diego think tank has worked to broker peace in hot spots including Nepal, Madagascar and the Ivory Coast, said Joyce Neu, executive director, who pegged Kroc's donations to the center at more than $30 million.

Kroc also had several San Diego-area causes. She contributed more than $90 million to the Salvation Army for a 12.5-acre arts and recreation center in east San Diego, an area that needs more public services, said Maj. Cindy Foley, the center's administrator.

The Salvation Army Ray and Joan Kroc Corps Community Center registered more than 420,000 visits in the 12 months after it opened in June 2002. It has three swimming pools, an indoor ice rink, a library and a $15 million theater.

"She worried that there were children and families who didn't have an opportunity to discover their talents because of a lack of facilities," Maj. Foley said. "She embodied the word generosity."

Kroc was born Aug. 27, 1928 in St. Paul, Minn., and was a musician and music teacher for many years. She married Ray Kroc in 1969 and the couple moved from Chicago to San Diego in 1976, two years after purchasing the Padres and preventing the team from being moved to Washington, D.C.

When Ray Kroc died on Jan. 14, 1984 at age 81, Mrs. Kroc succeeded him as the Padres' owner and chairwoman. She admitted knowing nothing about baseball when she took the helm, but that did not stop her from speaking out. The Padres went to the World Series in her first season, losing to the Detroit Tigers.

Kroc was deeply involved in running the team, at one point rehiring Manager Dick Williams after he was fired without her consultation. She sold the team in 1990, not because of the team's poor performance, she said, but because she wanted to spend more time with her family.

"I'm a few years older now, and, unlike Zsa Zsa (Gabor), I'm not ashamed to admit that I'll be 62 next August," she said in a 1989 interview. "I think it's time to prioritize."