Third base coach Dale Sveum will manage for the rest of the season.
"This was a very difficult move to make, and we appreciate all of the work that Ned has done to develop this team into a contender," general manager Doug Melvin said. "In the end, this was a collaborative decision made to put our club in the best position for the final two weeks of the season."
Milwaukee is hoping to avoid a repeat of last year's collapse. The Brewers held an 81/2-game lead in late June 2007 before sliding to 83-79 and missing the playoffs.
Yost was in his sixth season as the Brewers' manager. When Milwaukee hired him from the Atlanta Braves after the 2002 season, the team was in the midst of four straight seasons with 94 losses or more.
But the next three seasons resulted in records of 81-81, 75-87 and 83-79, much better for a franchise that hadn't had a winning record since 1992.
Yost spent 12 years on the Braves' coaching staff under Bobby Cox, and Atlanta won division titles every year except for the strike-shortened 1994 season.
Yankees: Catcher Jorge Posada wants Joba Chamberlain kept in the bullpen and predicts more injuries for the young pitcher if New York puts him into the starting rotation. "I think if you start him and he pitches 200 innings in one year, you're going to lose him. He's going to get hurt. I don't see him as a starter," Posada said during a session of CenterStage, scheduled to air on the team's YES Network on Sept. 28. Chamberlain began the season in the bullpen, then moved to the rotation in June. He was sidelined Aug. 4 to Sept. 2 because of rotator cuff tendinitis and went back to the bullpen when he returned. Chamberlain was 3-1 with a 2.76 ERA in 12 starts. He's 1-2 with a 2.29 ERA in 24 relief appearances.
Indians: The team has committed to playing in Cleveland through 2023. The club signed a new lease with the Gateway Economic Development Corp., a nonprofit organization that owns and operates Progressive Field, where the team plays. The previous lease was set to expire in 2013. The Indians began play at Progressive Field, then called Jacobs Field, in 1994.
Twins: Minnesota's new ballpark will be called Target Field. The team and Target Corp. announced an agreement in principle yesterday on an exclusive 25-year partnership that includes naming rights to the Twins' new stadium, scheduled to open in 2010.