Armand Hammer, the communist's son who became an American captain of industry as well-connected in the Kremlin as he was on Wall Street, has died at age 92.

Hammer died at his home Monday night after a brief illness, said Frank Ashley, a spokesman for Hammer's Occidental Petroleum Corp.Hammer, a self-made millionaire by the time he graduated from Columbia University medical school at age 23, was also a philanthropist, art collector and crusader for world peace.

"He was absolutely indomitable," said his attorney, Arthur Groman. "He never lost his courage or tenacity. In the last months, he was uncomplaining and optimistic."

Hammer exhibited a flair for the dramatic until the end, deciding to celebrate his bar mitzvah - which marks a Jewish boy's 13th birthday - at age 92. He died the night before the ceremony. Hammer was born a Jew, but his family did not follow religious customs.

"We're going to go ahead with the event," said spokesman Howard Bragman. "He's done extraordinary things for the Jewish people, and since (Tuesday) night is the first night of Hanukkah, we think that a light in the Jewish community like Dr. Hammer who did so much for Jewish freedom should be remembered." Hammer - a global businessman who knew world leaders from Vladimir Lenin to George Bush - negotiated deals with communist countries such as China and the Soviet Union to develop resources. For years, he urged American presidents to meet with their Soviet counterparts and encouraged the reduction of nuclear weapons, so the money could be diverted to agriculture and medicine.

"Armand Hammer was not only an observer, a witness to the decades in the history of Soviet-American relations, but also a man who actively participated in the building of those relations," said Soviet Foreign Ministry spokesman Yuri Gremitskikh.

Mikhail Gorbachev praised Armand Hammer for being "associated with some of the most valuable pages in Soviet history."

Gorbachev's spokesman, Vitali Ignatenko, said that Hammer "met (state founder Vladimir) Lenin and was close to the other Soviet leaders."

Hammer made several fortunes and gave huge sums to his favorite causes, especially cancer research. "The only reason I make money is so I can give it away," he was fond of saying.

After the Chernobyl nuclear accident in the Soviet Union, he arranged visits by U.S. specialists in bone-marrow transplants, which helped save radiation victims.

His empire rested on Los Angeles-based Occidental Petroleum Corp, which he bought for $100,000 in 1957 and turned into one of the nation's largest industrial companies.

Ray Irani, the company's president and chief operations officer, succeeds Hammer as chairman. Hammer's death makes the company a potential takeover target.

Hammer was born in 1898 in New York City. His Russian-born father, a doctor, was a founder of the American Communist Party.

But Hammer was a staunch capitalist who would say to communists, "I tell them that I don't think their system works. But that doesn't keep us from doing business."

After World War I, Hammer went to medical school at night and worked to bail out the family's struggling pharmaceutical firm.

He turned the business into a million-dollar company, in part because he was able to market tincture of ginger, sometimes used to give an alcoholic kick to ginger ale during Prohibition.

After the Bolshevik Revolution, Hammer worked out a deal to trade surplus U.S. grain for Soviet products. Hammer became a Soviet hero for helping ease food shortages in the embattled country.

For the next 25 years, he was an art dealer, a cattle breeder in New Jersey and a whiskey distiller in Kentucky.

In 1940, he parlayed a $100,000 investment into $7.5 million by making blended whiskey from potatoes.

Hammer bought Occidental as a tax shelter when it was near bankruptcy. Today the company boasts huge oil, natural gas, coal, chemical and agribusiness operations.