NEW YORK — Baseball umpires and management signed an agreement Wednesday that will allow the sport to start using instant replay to help determine calls on the field.

Major League Baseball still hasn't determined when the use of replays will start. Installation of equipment has been going on at ballparks, and officials have said they hoped to start using replay in August.

Replays will be limited to boundary calls, such as determining whether fly balls were fair or foul, or whether they went over fences.

"I told our members that it's just another tool that we can use to get the play right, not to look at it as a negative, but a positive," World Umpires Association president John Hirschbeck said. "As hard as you try, as much as you hustle, sometimes with just the landscape of the ballparks nowadays, it's hard to tell. So if we can get it right, you know what, let's use it as a tool to get it right."

The deal was signed by management lawyer Dan Halem and WUA attorney Brian Lam one day after a WUA spokesman went public with complaints over negotiations.