Crane signed a sales purchase agreement in May to buy the team from Drayton McLane for $680 million, but Major League Baseball has yet to approve the deal. The possible switch of leagues has kept the deal from being approved, the source said, but it could still get approval without Crane's consent to switch leagues.
McLane declined to comment Thursday, and Crane didn't respond to an e-mail seeking comment.
Last month, Major League Baseball postponed a planned vote on the transaction during the owners' meetings, saying it needed more time to examine the deal.
In an interview with the Houston Chronicle on Thursday, Crane acknowledged that approving a move to the AL may be holding up the deal. He also said the agreement he has with McLane has a Nov. 30 deadline.
"When that expires, then it expires," Crane told the newspaper. "The contract goes through Nov. 30. You know, that's a pretty standard process when you sign a deal like that."
Crane said a move to the AL West would have significant financial ramifications for the Astros, including increased travel costs, as well as adding a designated hitter to the payroll.
"We signed an agreement in May, and that agreement hinges off all the economics that were presented to us," he said. "We're paying a very handsome sum for the team, and that was based off the deal that was presented to us. That was a signed contract, and we will honor that contract. If that changes, we've told baseball that if they want us to move to the American League we'd certainly consider that, but we have to understand all the ramifications of that. That includes travel, that includes paying for a designated hitter that we don't have to pay for. That includes our TV contract."
The Astros, who have played in the National League in all 50 years of their existence, could be moved to the AL to give each league 15 teams and perhaps pave the way for a second Wild Card playoff team from each league.
Major League Baseball Players Association executive director Michael Weiner said in July the idea of having two 15-team leagues, which would require year-round Interleague Play, appealed to the players. Selig told reporters at the All-Star Game that "massive realignment" wasn't on the horizon.
Any possible realignment wouldn't likely take place until 2013 at the earliest, considering 2012 schedules will be released soon.
The Astros currently play in the NL Central, which is the only six-team division in baseball. The AL West is the only division with four teams, so moving the Astros into a division with their in-state rival Texas Rangers appears to make the most sense geographically. The Los Angeles Angels, Oakland A's and Seattle Mariners are also in the AL West.
McLane previously had said he was against a move to the AL West because it would result in an increase in the number of late West Coast start times. The Astros played in the NL West from 1969-1993, a division that included the Cincinnati Reds and Atlanta Braves.
A move to the AL would also require the Astros to start using a designated hitter, something they're currently required to do only in games in AL ballparks during Interleague Play.
Crane has been kept in the loop about the Astros' moves this year, which included the July trades of outfielders Hunter Pence and Michael Bourn -- the team's two best offensive players -- in exchange for prospects and outfielder Jordan Schafer.
Crane's group also will take ownership of the Astros' stake in a regional sports network, in which the team has partnered with the NBA's Houston Rockets and Comcast. It will begin airing Astros games in 2013 and Rockets games beginning with the 2012 preseason.
Crane is the chairman and founder of Houston-based Crane Worldwide Logistics and the former chairman, CEO and majority shareholder in Eagle Global Logistics (EGL), which provides heavyweight freight transportation and related logistics services.
A native of St. Louis, he received a bachelor of science degree in industrial safety from the University of Central Missouri, where he was a standout baseball pitcher for the Division II school from 1973-76.
McLane bought the team in 1992 for $117 million. In McLane's tenure as owner, the Astros made the playoffs six times in a nine-year span, including the team's first World Series berth in 2005.