NEW YORK (AP) — Donald Fehr is retiring as head of the baseball players’ association after more than a quarter-century in charge of the powerful labor union.

Fehr, who turns 61 next month, said Monday he will retire no later than the end of March.

Subject to approval by the union’s executive board, he will be succeeded by union general counsel Michael Weiner, his longtime heir apparent. Weiner will head negotiations heading into the expiration of the current labor contract in December 2011.

“I have no hesitancy in recommending to the players that he be given the opportunity to do this job,” Fehr said.

A clerk to a federal judge who became the top lawyer to pioneering union head Marvin Miller in August 1977, Fehr took over as acting executive director on Dec. 8, 1983. That was 2½ weeks after players fired Kenneth Moffett, the former mediator who had succeeded Miller following a 50-day strike in 1981,

Fehr led players through a two-day strike in 1985, then was voted executive director on a full-time basis that December. His early years in charge were defined by management’s conspiracy against free agents. The union successfully charged management with conspiring against free agents following the 1985, 1986 and 1987 seasons in violation of the labor contract and settled the cases for $280 million.

When he first assumed the top job 26 years ago, the average salary was $289,000. It had risen to $2.9 million by last year. But while players made tremendous economic gains and fended off management’s repeated attempts to obtain a salary cap, he has been criticized by some for not agreeing to drug testing until August 2002.

He presided over three work stoppages during his time in charge, with the brief 1985 strike followed by a 32-day lockout in 1990 and a 7½-month strike in 1994-95 that wiped out the World Series for the first time in 90 years. That stoppage ended only when the National Labor Relations Board, at the union’s behest, obtained an injunction to restore work rules from U.S. District Judge Sonia Sotomayor, nominated last month by President Barack Obama for the Supreme Court.

There has been labor peace since then, with the current collective bargaining agreement running through the 2011 season, and Fehr developed a businesslike if not warm relationship with Bud Selig, baseball’s commissioner since 1992.

A bookworm happier to discuss the latest essay in Scientific American rather than baseball, Fehr led a casual union in which he showed up to work most days in jeans and sneakers, keeping a jacket and tie in an office closet in case he needed to go on television.

He was working at the law firm of Jolley, Moran, Walsh, Hager & Gordon in Kansas City, Mo., after clerking for a federal judge when Miller and Dick Moss, then the union’s general counsel, needed a lawyer to help defend the owners’ appeal of the Andy Messersmith-Dave McNally case, in which arbitrator Peter Seitz overturned the reserve clause. Fehr had been working on cases involving the steelworkers.

“It was really all an accident,” Fehr said in 1985. “Marvin and Dick both came out of the steelworkers, so they went to our firm. Originally, someone else was going to handle it. But I was eventually asked to do their work.”

When Moss quit the union to become an agent, Fehr was hired by Miller as Moss’ replacement.

“I had become fascinated with baseball labor-management relations during the Messersmith case and decided to take the job and move to New York,” Fehr said.

Weiner, the longtime No. 3 official, has been with the players’ union since September 1988 and has been its general counsel since February 2004. The No. 2 official is Gene Orza, the union’s chief operating officer.