Hans Sennholz, a retired Grove City College professor and a well-known and influential free-market economist whose libertarian and privatization philosophies influenced Reagan administration economic policies in the 1980s, died Saturday in Grove City Hospital following a brief and unspecified illness.

Mr. Sennholz, 85, who taught economics at Grove City from 1956 until 1992 and was a proponent of Austrian economics, was a prolific writer and lecturer on a variety of economic, social and political issues, often flying his own plane to lecture destinations across the country.

"He was a big influence on 'Reaganomics' and the current conservative movement and helped in the resurgence of free-market economics, not only in the United States, but also in Eastern Europe, India and around the world," said Camille Castorina, an economist and former student at Grove City.

She said he was a friend of Milton Friedman, the Nobel Prize-winning economist and proponent of laissez-faire economics, and an influence on Edwin Feulner, founder and president of the conservative Heritage Foundation, but never achieved their notoriety because he chose to remain at Grove City College, in Mercer County, teaching undergraduates.

"He preferred to teach undergraduates because they were more passionate about things and their minds were more malleable," Ms. Castorina said. "He was very inspiring in the classroom, and taught many stockbrokers and bankers influential in the Pittsburgh banking community."

A native of Germany who retained a slight German accent throughout his life, Mr. Sennholz was drafted into the German Luftwaffe during World War II and flew numerous missions as a fighter pilot in France, Russia and North Africa until he was shot down and captured.

He spent the last part of the war in prisoner camps in the United States.

When the war was over, he went back to Germany where he received degrees at Marburg University and Cologne University. He returned to the United States in the early 1950s and studied at New York University, earning his doctorate in economics.

In his 37 years at Grove City, he taught more than 10,000 students, wrote more than 1,000 books, booklets and articles, and received numerous awards and honorary degrees.

Mary Sennholz, 93, his wife, said her husband met Ronald Reagan after a speech in the late 1970s in Honolulu.

"It was after his time as California governor but before he was president," she remembered yesterday. "We went up to him and I introduced my husband and Reagan knew him and said to him, 'Well, hello. I've been plagiarizing your work in my newspaper column for years.' My husband responded, "You've been reading good material.' "

In addition to his wife, he is survived by a son, Robert, of Grove City, and two grandsons.

Friends and family will be received from 7 to 9 p.m. today at Cunningham Funeral Home, 306 Bessemer Ave., Grove City. A funeral service will be held at 11 a.m. tomorrow at Holy Trinity Lutheran Church, 819 Columbia Ave., Grove City.

A second viewing will be held from 7 to 9 p.m. tomorrow at the Bethesda Church, Swamp Church Road, Farmers Mills. A funeral service will be held there at 10 a.m. Wednesday, with interment to follow.