MILWAUKEE -- Baseball will be making major changes in the next two years -- adding two teams to the playoffs, moving the Houston Astros to the American League and extending interleague play to September.

The expanded playoffs could come as early as next year. That will put 10 teams in the postseason, requiring a new wild-card playoff round that probably will be one game, winner take all.

The altered playoff structure is subject to an agreement on a new labor contract with the players' association, which is expected before the current deal expires Dec. 11.

"We believe after a lot of study and a lot of thought that the addition of two wild cards will really help us in the long run," said Commissioner Bud Selig, who called it a "historical" morning.

Baseball began its playoff system in 1969 and doubled the playoff teams to eight in 1994, a change delayed one year by a strike. This change will put one-third of the baseball's 30 teams in the postseason. In the NFL, 12 of 32 teams make the playoffs. In the NBA and NHL, 16 of 30 teams advance.

Selig acknowledged that additional wild-card teams would have eliminated the drama on the final night of this season, when Tampa Bay overtook Boston and St. Louis moved past Atlanta.

"You don't do things for one year. You do things for a long period of time," Selig said.

As a condition for approving the sale of the Astros from Drayton McLane to Jim Crane, the Astros agreed to shift from the NL Central to the AL West as soon as 2013, giving each league 15 teams. It's baseball's first realignment since the Milwaukee Brewers went to the NL after the 1997 season.

"It won't be perfect. Nothing in any schedule is ever perfect," Selig said, "but this will be very good."

With an odd number of teams in each league, there will be interleague play from April through September. Since interleague games began in 1997, they had been concentrated around May and late-June.

The Astros, part of the NL since joining the majors in 1962, will be getting plenty of frequent flier miles. Instead of going to cities in the Midwest several times a year, they'll be headed out to Anaheim, Oakland and Seattle.

"I was in the air freight business and we were always flying a lot. So, we'll be flying a lot," Crane said.

But they'll have a built-in rivalry with the two-time AL champion Texas Rangers.

"I'm proud of the changes, but you want to be sure you're always doing the right thing. This is the thing we've studied for a long time, but they'll be working on schedules in the future," Selig said.

The shift, approved unanimously, does not appear to be popular with fans.

"I don't like how they did it, sort of strong-arming it," 47-year-old Eddie Fuller of Houston said at a sports bar near Minute Maid Park.

"I prefer the National League myself. I'm not a big DH fan. I just like National League baseball better," said Fuller, who estimated he goes to 30-40 Astros games each year.

An expanded playoffs has been debated for a year, since union head Michael Weiner said players were open to it. Players also pushed for 15-team leagues because they felt it was harder to make the postseason from the six-team NL Central and easier from the four-team AL West.

"We haven't come to a final decision but if I had to take a guess today it would be one game," Selig said. "Baseball people, my 14-man committee, all wanted one game. The only guy who had concerns about it was me. They like the one game. It'll be dramatic. One game will be good."

As part of the Astros' agreement to switch leagues, the sale price was cut from $680 million to $615 million, a person at Thursday's meeting told The Associated Press. The person spoke on condition of anonymity because details weren't announced.

Major League Baseball will make up part of the $65 million difference, paying McLane $35 million over three years, the person said.

Owners also approved longtime San Francisco Giants executive Larry Baer to replace Bill Neukom as the team's controlling owner.

In addition, MLB executive vice president Rob Manfred said progress was made on a new labor contract. The deal could fall into place before Thanksgiving.

"I'm really confident. I think we will finish an agreement," Manfred said. "As for the process, it's hard to predict exactly when anything is going to happen. I think we've made good progress and I'm hopeful that we'll push it across the finish line."

Selig saluted McLane, who bought the Astros in 1992 for about $117 million. The Astros were a major league-worst 56-106 this year, setting a team record for losses.

"Drayton should have a wonderful legacy of what he did for the Astros, got them a new ballpark and did all these things," Selig said. "He sure left a much better franchise than we he came in."

Crane founded a Houston-based logistics company in 2008. He is chairman and chief executive officer of Crane Capital, a private equity fund company. Two years ago, he was attempting to buy the Chicago Cubs and last summer he tried to purchase the Texas Rangers.

In September, Crane expressed frustration at how long it was taking MLB to approve the sale, which was announced on May 16, and noted there is a Nov. 30 deadline. The sale had been placed on the agenda for a vote in August, then was removed.

In 1997, employees of Crane's former company, Eagle USA Airfreight, filed complaints with the Equal Employment Opportunity Commission saying there was discrimination. Eagle settled the case in 2005 for about $900,000.

Selig acknowledged the long vetting process.

"We did spend an enormous amount of time and I'm very comfortable today that he has put together a really blue-ribbon group in Houston," Selig said. "I'm relieved today. It's over, and I'm happy. The group represents the entire Houston community and I think they'll do very, very well."

Owners were given a report on the bankrupt Los Angeles Dodgers. While owner Frank McCourt reached a still-secret agreement with baseball to sell the franchise following months of litigation, the team and the Fox division of Rupert Murdoch's News Corp. are fighting over McCourt's desire to market media rights from 2014 on as part of the process.

A sale would give McCourt the money to pay his divorce settlement by the April 30 deadline he agreed to.

Asked whether it was awkward having McCourt in the meeting. Selig said no.

"All of that went as well as it could today," he said.