NEW YORK -- Major League Baseball announced Tuesday that it will enact instant replay for home run calls this week, becoming the last of the four major North American sports leagues to do so.

The use of replay will start on Thursday. Like the NHL and NBA, replay will only be used in specific circumstances -- to decide if a home run cleared the fence, in fair/foul calls on homers, or to decide if there was fan interference.

"I believe that the extraordinary technology that we now have merits the use of instant replay on a very limited basis," said MLB commissioner Bud Selig. "The system we have in place will ensure that the proper call is made on home run balls and will not cause a significant delay to the game."

The replay will debut on Thursday in Chicago, where the Cubs host the Philadelphia Phillies, in Anaheim, where the Los Angeles Angels host the Texas Rangers, and in Oakland, where the Athletics host the Minnesota Twins. Replay will begin everywhere else starting on Friday.

Technicians will be paired with either umpire supervisors or former umpires at Major League Baseball Advanced Media (MLB.com) headquarters in New York, where they will view television broadcast feeds from all games. A television monitor and a telephone line to MLB.com, placed next to the monitor, have been installed at every Major League ballpark.

If the crew chief elects to use replay, he will call the MLB.com technician, who will control the video feed to the monitor at the ballpark. The decision to reverse a call will be up to the crew chief. There must be "clear and convincing evidence" to change a decision made on the field.

Players and coaches will not be permitted to argue the results of an instant replay decision. Should a home run call be reversed, decisions regarding the placement of runners will be made by the crew chief, who will place the runners where he believes they would have been had the call been made properly.

MLB's general managers voted 25-5 last November to ask the league about exploring the possibility of using instant replay on a limited basis. Almost 10 months later, after working out agreements with the unions for players and umpires, the league is ready to go to replay.

Replay will remain in effect throughout the current Collective Bargaining Agreement, which ends in 2011, unless either the umpires or players union objects.

"We are pleased that we were able to reach this agreement," said players union chief Donald Fehr. "Following the World Series, the players will review the matter, and then determine what course to take for the future. While the use of instant replay is an experiment, we hope that over the balance of this season it will prove to be a success."

Selig reiterated in a conference call on Tuesday that replay will not expand.

"My opposition to unlimited instant replay is still very much in play. I really think that the game has prospered for well over a century now by doing things the way we did it," said Selig.

"But when you look at the technology we now have, and the new ballparks, and even some of the old ballparks that have been reconfigured, there's no question that it was a challenge to the umpires ... Like anything else in life there are times when you need to make an adjustment,"

MLB is the last major professional sports league in North America to go to replay, which debuted in the NFL in 1986. The NFL, which dropped replay in 1992 only to bring it back in 1999, is still the only league to use replay for a wide variety of calls, and the only one to allow coaches to decide when a play is reviewed.

The NHL began using video replay in the 1991-92 season to check goals and, like MLB, the NHL uses a central location -- in Toronto -- to control review video feeds. The NBA has used replay to check last-second shots since the 2002-03 season, and last season began using video in situations involving fights or flagrant fouls.