A group headed by Jim Crane purchased the team from Drayton McLane with the stipulation the Astros will move from the National League to the American League in 2013.
MLB.com reported the agreement by Crane to move his new team from one league to the other earned him a reduction in the sale price from $680 million to $610 million.
Commissioner Bud Selig also announced Thursday that the baseball playoffs would be expanded to include an additional wild card from each league and that there would now be three rounds in the post-season.
The expansion means a third of the teams in MLB will participate in the chase for the World Series title. Although it has yet to be made final, Selig said it is likely the first playoff round will consist of a one-game showdown between the wild card participants from each league.
With the move by the Astros to the AL, each league will now have 15 teams. That, in turn, ensures inter-league play will be a part of baseball's schedule throughout each season.
"I welcome Jim Crane and his group as they prepare to become the new stewards of the Astros," Selig said. "I thank them for their patience and determination throughout a long but necessary process, which allowed us to accomplish our due diligence. The enthusiasm of Jim and his group will serve the Astros and their fans very well in the years ahead."
Houston's move will be made from the NL Central to the AL West, where the Astros will join Texas, Seattle, Oakland and the Los Angeles Angels. Houston has been in the National League since being created as an expansion team in 1962.
Crane had previously attempted to purchase the Chicago Cubs in 2009 and the Texas Rangers in 2010.