The Pittsburgh Pirates, charging that Dave Parker's "improper, illegal and heavy use of cocaine" seriously affected his baseball performance, filed a civil suit today to halt $5.3 million in deferred payments owed the Cincinnati Reds' outfielder.

The suit, the first of its kind against a major league player, according to new Pirates President Malcolm Prine, contends Parker concealed his drug use before signing a five-year contract in 1979.

Parker testified in federal court last summer during the drug trafficking trial of sometime Philadelphia Phillies clubhouse caterer Curtis Strong that he began using cocaine in 1976 and was a regular user from 1979 -- a year the Pirates won the World Series -- until 1982, but stopped after it began affecting his play. He signed with Cincinnati as a free agent after the 1983 season.

The Pirates apparently are basing their case on a clause in the 15-page contract in which Parker certified he had "no physical or mental defects known to him . . . which would prevent or impair performance of his services."

The suit filed by the new ownership, Pittsburgh Associates, claims "the deterioration of Parker's skills as a player and his failure to stay in good physical condition . . . were directly related to and caused by his . . . use of cocaine."

After signing the contract, the suit says, Parker "stole fewer bases, his fielding ability significantly deteriorated, and he generally failed to perform up to the level achieved by him prior to 1979."

In 1978, Parker had won his second consecutive National League batting title and was league MVP.

"He failed to keep himself in good physical condition, with his weight ballooning at times to in excess of 270 pounds, as a result of which he became injury-prone," the suit added.

The deferred payments call for Parker to receive $944,445 in January 1988 and monthly payments of nearly $20,000 through 2007.

The lawsuit does not mention any attempt to recover the estimated $2,125,000 already paid Parker under the contract -- a $625,000 signing bonus and base salary of $300,000 for each of five seasons.

Reached by the Pittsburgh Post-Gazette, Parker said, "Oh man . . . another hurdle I've got to leap. Why don't they just leave me alone?"