A report in last Wednesday's Washington Post mistakenly said that former Illinois Gov. Otto Kerner had been pardoned three days before his death in May, 1976, for a federal tax fraud conviction. In fact, the Department of Juctice only agreed to waive guidelines regarding Kerner's application for the pardon, which is still under considerations.

The conviction yesterday of Maryland Gov. Marvin Mandel marks only the third time in the nation's history that a sitting chief executive of a state has been found guilty of a federal crime.

In 1924, Gov. Warren T. McCray of Indiana was jailed for using the mails to defraud. He resigned after being sentenced to 10 years. He was paroled in 1927.

William A. Langer, governor of North Dakota, was removed from office in 1934 after being convicted of conspiracy to obstruct operation of federal recovery and relief legislation.

Langer's story has a happy ending. His conviction subsequently was overturned and he returned to the governor's chair in 1937 after running as an independent. Then, three years later, he began a 19-year career as a U.S. senator.

Other governors also have run afoul of the law, but not until they had left office. Former vice president and ex-Maryland Gov. Spiro Agnew is the best-known. He pleaded no contest to one count of income tax evasion. That violation cost Agnew his job as Vice President four years ago. Mandel followed Agnew as governor.

Former Illinois Gov. Otto Kerner was a judge on the U.S. Court of Appeals for the Seventh Circuit when he was indicted, tried and convicted in 1973 of mail fraud tax evasion and perjury. The charges were in connection with Kerner's purchase of race track stock at prices well below market value while he was governor.

Kerner was the first sitting U.S. appeals court judge ever convicted of a felony. He died in May, 1976, little more than a year after he had been paroled and three days after President Ford had pardoned him.

Two other ex-governors also have gone to prison during this decade. W.W. (Wally) Barron of West Virginia was sentenced to 25 years for bribing the foreman of a jury that acquitted him of charges that he sought kickbacks on contracts awarded by his administration.

Barron, who was governor from 1961 to 1965, was paroled in 1975.

David Hall, former governor of Oklahoma was given a three-year sentence for trying to bribe the Oklahoma secretary of state for seeking his influence in the investment of state retirement funds. Hall also was convicted of four counts of extortion in a trial that ended in March, 1975, three months after he left office. He was sentenced a month later to three years in jail.

Louisiana Gov. Richard Leche left office in 1939 when federal inquiries began into his conduct. Leche later was convicted of mail fraud.