ARLINGTON -- The Rangers' annual Lone Star Series with the Astros will become a division rivalry in 2013.

Major League Baseball announced on Thursday that the Astros are moving to the American League West in 2013. The move was announced after the sale of the Astros to a group headed by Jim Crane was formally approved at the Owners Meetings in Milwaukee.

The AL West had been a four-team division along with the Mariners, Athletics and Angels since 1994. The new five-team division will give the Rangers a rival within the Central time zone.

"I think it's great for our fans," Rangers infielder Michael Young said Thursday. "Any time we play division games on the road, our fans are forced to wait until 9 p.m. for start times. For the players, it will be nice to finally have convenient travel for at least one division team."

The Rangers and the Astros have been playing a home-and-home Interleague series since 2001. The arrangement was part of a compromise between Major League Baseball and former Rangers owner Tom Hicks.

When the Milwaukee Brewers moved to the National League Central, it was supposed to be just the first step in the realignment process. The next step was supposed to be moving the Rangers out of the West and into a Central time zone division. But Major League Baseball was unable to make it work, and Hicks was willing to stay in the AL West in exchange for the annual home-and-home series with the Astros.

Now they will be in the same division and playing more than six times a year, although scheduling details have not been announced. The Rangers had been playing 19 games each against the Mariners, Athletics and Angels while making three trips to each city a year. The addition of the Astros obviously means fewer games and trips to the West Coast.

"I don't think it changes how we go about building the club to compete in our division," general manager Jon Daniels said. "But I'm interested to see what the impact is on Interleague Play, how many more games we'll play with NL rules and whether we need to factor that into how we put the roster together."

The Rangers have won five straight Lone Star Series and seven of the last eight. They are 21-9 against the Astros since the beginning of the 2007 season, including four of six in 2011.

"From our perspective, having them in our division, I like it, because it gives us another team in our time zone and we're at a disadvantage in our division that way because so many of our games start at 9 o'clock and it hurts our TV ratings," Rangers president Nolan Ryan said. "I think that if both teams are competitive in a given year, I think it will create a good rivalry within the state. I think there are a lot of pluses from our perspective about it."

The Astros began play as an expansion team in 1962, one year after the second Washington Senators team was formed. They could have been in the same division as a team from North Texas beginning in 1969. Major League Baseball expanded by four teams that year and former Arlington mayor Tom Vandergriff was pushing for the National League to expand to North Texas.

But Astros owner Roy Hofheinz blocked the move and the National League expanded to San Diego instead. Four years later the Senators moved to Arlington.

Outside of California, which has five teams, the Rangers and the Astros will be the only two clubs from one state playing in the same division. Teams from Missouri, Illinois, New York, Ohio and Florida are separated by leagues. The Pirates and the Phillies are both in the National League, but the two Pennsylvania teams play in different divisions.