Major League Baseball told Houston businessman Jim Crane it would not approve his purchase of the Astros unless he agreed to move the team to the American League, The Associated Press has learned.

Crane was forced to agree to move the sale along, a person familiar with the negotiations said Wednesday on condition of anonymity because no official announcement has been made by MLB or the Astros. Approval of the sale could be announced as early as Thursday at a meeting of baseball executives in Milwaukee.

Crane reportedly agreed to the move in exchange for a drop in the sales price valued earlier this year at $680 million. The person who spoke to the AP could not confirm the sales price.

The MLB Players Association believes two 15-team leagues would create a more proportionate schedule and has urged baseball to make the switch. With schedules for next season already completed, the earliest such a move could take place is 2013.

Time is running out for approval of the deal: Crane has said that his offer, which was announced on May 16 expires Nov. 30.

An MLB spokesman did not immediately return messages seeking comment, though Commissioner Bud Selig addressed an Astros' move during a Twitter chat on Monday.

"For 15/15 realignment, Houston would be the team moving to AL West. Would create more fairness in baseball," Selig tweeted via the Colorado Rockies Twitter feed. He also added that "15 teams in each league would necessitate interleague play every day but it will be better schedule overall."

The Astros currently play in the six-team NL Central. The AL West is the only league in the majors with four teams (Rangers, Angels, Athletics and Mariners).

The Astros would be in a division with in-state rival Texas. But fans are unhappy that the other three teams are all on the West Coast, meaning many road games would routinely end past midnight Central time.

Drayton McLane bought the team in November 1992 for about $117 million and put the franchise up for sale in November. He turned down an offer from Crane to buy the team in 2008.

The $680 million sale price is the second-highest in major league history, trailing the $845 million purchase of the Chicago Cubs by the Ricketts family two years ago. The $660 million sale of the Boston Red Sox in 2002 currently is second. Like the Astros' deal, the Cubs and Red Sox transactions included related entities.

A major selling point in Houston was the Astros' share in a new deal with the NBA's Houston Rockets to create a regional sports network that will begin airing Rockets games in 2012 and the Astros in 2013. Crane has said the team's 30-year lease at Minute Maid Park, which is owned by the Harris County Houston Sports Authority, will remain intact under his ownership.

Crane, who founded a Houston-based logistics company in 2008, is also the chairman and chief executive of Crane Capital, a private equity fund company. In 2009, he was in the running to buy the Cubs and last summer teamed with Dallas Mavericks owner Mark Cuban in an unsuccessful bid to buy the Texas Rangers.