Marvin Miller, the founding chief of the Major League Baseball Players Association who changed the landscape of sports by pioneering free agency for players, died on Tuesday at the age of 95, the union said.

Miller, who used the collective bargaining process and some stormy work stoppages to win players the right to become free agency along with vastly improved pensions, health benefits and pay, died at his New York home after a battle with liver cancer, the union said.

"All players - past, present and future - owe a debt of gratitude to Marvin, and his influence transcends baseball," current union head Michael Weiner said in a statement.

"Marvin, without question, is largely responsible for ushering in the modern era of sports, which has resulted in tremendous benefits to players, owners and fans of all sports.

"His legacy will live on forever."

Miller, who led the union from 1966-82, battled the club owners in the courts and at the bargaining table to eliminate MLB's long-standing reserve clause that had made players the property of the team beyond their contracts.

Through his efforts baseball players gained the freedom to sell their services in a virtually unrestricted market after satisfying an initial term of service.

Beginning in 1976, players were able to hit the open market, forever changing the way teams could build their rosters, and the success of the baseball players union fueled collective bargaining advances by unions in other major team sports.

The road to free agency and other changes did not come easily.

During Miller's tenure the players staged short strikes in 1972 and 1980 and a 50-day stoppage during the 1981 season. Owners locked out players for 17 days during spring training in 1976.

"Marvin Miller was a highly accomplished executive and a very influential figure in baseball history," MLB Commissioner Bud Selig said in a statement.

"He made a distinct impact on this sport, which is reflected in the state of the game today, and surely the Major League players of the last half-century have greatly benefited from his contributions."