One of the nation's wealthiest women--and the only woman to head an American oil company--has been fined $500 and sentenced to 200 hours of public-service work for personally ordering the rigging of gasoline pumps to shortchange customers.

The sentencing of Mary Hudson Vandegrift came Tuesday in an Olathe, Kan., circuit court after the 70-year-old chairman of the board of Hudson Oil Co. pleaded no contest to the felony-theft charge. She also was sentenced to two years' probation. She could have been sentenced to up to five years in jail.

Vandegrift, of Mission Hills, Kan., was listed last year by Forbes Magazine as one of the nation's 400 wealthiest individuals.

Court records said Vandegrift ordered one of her Kansas-area marketing managers, Robert Monroe Neuffer, to break the state seals on pumps and then readjust the pumps so that customers received eight to nine cubic inches less than they deserved on a five-gallon purchase.

The amount of gasoline involved was all but indiscernible to the average customer. Kansas law requires pumps to be accurate within three cubic inches for a five-gallon purchase.

But Neuffer, testifying under immunity from prosecution, said in court documents that he tampered with pumps in 16 states, including Maryland and Virginia. Neuffer said he attached new seals to pumps to cover the tampering.

The charges against Vandegrift have led to filing of at least three class-action civil suits, including one by six Kansas City residents seeking $20 million in punitive damages from Hudson.

Arthur J. Kase, attorney for the Hudson customers, said the $20 million figure was based on the estimated $120 million net worth of Vandegrift and the company.

"The individual overcharges were not great," said Kase, "The amounts would be too small for any individual to take legal action. But the total is great."

Kase has asked that the suit be expanded to cover consumers who may have been defrauded in other states.

Hudson Oil operates gasoline stations in 34 states. Neuffer testified that he tampered with pumps in Florida, Illinois, Indiana, Kentucky, Michigan, Minnesota, Missouri, Nebraska, New York, Ohio, Pennsylvania, West Virginia and Wisconsin as well as Kansas, Virginia and Maryland.

Johnson County, Kan., District Attorney Dennis Moore, who had asked for the maximum fine of $10,500 but no jail sentence for Vandegrift, said he did not know if criminal charges had been filed in other states.

But Moore said Kansas Attorney General Robert Stephan planned to notify prosecutors in the 15 other states in which Neuffer said he illegally adjusted the pumps.