SCOTTSDALE, Ariz. — Major league umpires Monday night overwhelmingly ratified a new five-year contract that included increased flexibility on postseason assignments.

The contract, which runs through 2014, does away with the prohibition against umpires working the World Series in consecutive seasons, a provision some in the union originally found difficult to digest.

Management sought to add that language after a series of missed calls in the 2009 playoffs.

“Baseball and the union both agreed to make every effort to keep the game of baseball first and professional umpiring second, and we’re going to do what’s in our hearts to make it right. We said that from the beginning, and we kept our word,” said Joe West, the president of the World Umpires Association.

“I think all the umpires are very happy. It was a good day for baseball and a good day for umpires.”

West said all 68 major league umpires attended the meeting, which last five hours.

The change to allow umpires to work consecutive World Series was a touchy subject, the union admitted.

“We think it’s in baseball’s best interest to develop a lot of umpires with World Series experience,” union attorney Brian Lam said.

Nevertheless, West said the ratification “was the biggest passing vote I’ve seen.”

Postseason assignments had been made on merit basis since 1981, but umpires could not work consecutive World Series.

The new agreement will enable management to use video to evaluate umpires and will establish new guidelines for retirement.

Baseball owners unanimously ratified the new agreement Thursday at their meetings in Arizona.

The contract acceptance insures the first decade of labor peace with the umpires since the 1960s.

“I think we all get smarter in our old age,” West said.

The contract was the second negotiated without incident since 1999, when 22 umpires lost their jobs in a failed mass resignation.

The labor pact between baseball and the players union expires in December 2011.

The WUA was formed in 1999, after Richie Phillips’ Major League Umpires Association lost its power when mass resignations failed. New union president John Hirschbeck negotiated two labor agreements with major league baseball before West succeeded Hirschbeck last February.

A 14-member committee formed by commissioner last week said it is discussing the possible expanded use of instant replay. Umpires currently use instant replay to review home run calls.