Plato Malozemoff, the former chairman and chief executive of the Newmont Mining Corporation, died Aug. 8 1997 at Greenwich Hospital in Greenwich, Conn. He was 88 years old and lived in Greenwich. The cause of death was congestive heart failure, his son, Alexis, said. Mr. Malozemoff was born in St. Petersburg, Russia, while his father, Alexander, was in exile in Siberia, managing a British-owned gold mine. In the early 1920's, soon after the Russian Revolution, the family was banished from the Soviet Union and settled in California. Mr. Malozemoff earned degrees from the University of California at Berkeley and from the Montana School of Mines, but he was unable to find full-time employment. For several years, he held jobs under the Works Progress Administration, the Government employment program set up during the Depression. He eventually accepted a positon as a mining engineer with Newmont in 1945 and quicky rose to become vice president in 1952 and president and chief executive in 1954. He was named chairman in 1966 and held the company's most senior positions until his retirement in 1986. Under his leadership, Newmont grew from a small holding company with a market value of about $147 million to a large international mining corporation valued at $2.3 billion at the time of his retirement. The company held interests in coal, gold, copper, oil and other resources in Peru, South Africa and Australia, among other places. His many civic associations included serving as a director of the Boys and Girls Clubs of America and a trustee of the American Museum of Natural History. Mr. Malozemoff is survived by his wife, Alexandra, and two children: Alexis of Lexington, Mass., and Irene Weigel of Lincoln, Mass.