LOS ANGELES (AP) _ Frances Hammer, wife of industrialist Armand Hammer, died Saturday morning of pneumonia after undergoing surgery for a broken hip, a spokesman for Occidental Petroleum Corp. said. She was 87.

Mrs. Hammer died at the University of California-Los Angeles Medical Center, said Occidental spokesman Frank Ashley. Hammer, 91, was at the medical center when she died, Ashley said.

She was a constant companion and adviser to her husband for the past 33 years, accompanying him as he pursued philanthropic and business interests as chairman of Occidental. She also helped Hammer in his effort to find a cure for cancer.

Mrs. Hammer was a painter, supported the arts and was involved in several civic and charitable activities, Ashley said.

The Chicago native and Hammer were married in January 1956. It was his third marriage and her second.

Mrs. Hammer was a co-founder of the International Student Center at the University of California-Los Angeles, with Neil Jacoby, former dean of UCLA's School of Biology.

She also served on the Campobello International Park Commission, which oversees the U.S. and Canadian International Peace Park at the retreat of former President Franklin D. Roosevelt. Hammer bought the retreat and gave it to the governments of both countries.

Mrs. Hammer was a charter member of the board of directors of the Armand Hammer United World College of the American West in Montezuma, N.M. She participated in conferences on international peace and human rights sponsored by Hammer.

In 1981, she was honored in Los Angeles by the American Women for International Understanding, of which she was a member. She was also a member of the Blue Ribbon 400 support group for the Los Angeles Music Center.

She is survived by three sisters, a niece and two grand nephews.

The Hammers had no children. Funeral services were to be private.