MUNICH, Germany (Reuters) - The conservative premier of Germany's Bavaria region resigned on Wednesday, following heavy losses in a state election that look sure to increase tensions in German Chancellor Angela Merkel's government.
Premier Guenther Beckstein, in office for only a year, said he would step down because he lacked both voter support and backing inside his Christian Social Union (CSU), the sister party to Merkel's Christian Democrats (CDU).
The 64-year old's move, coming just a day after CSU leader Erwin Huber announced his resignation, has raised the political risks for Merkel one year before a federal election.
"Unfortunately, voters' support was significantly weaker than I expected," Beckstein said about the CSU's election result -- its worst in the southern state in 54 years.
"After the painful defeat, I notice that my support within the party...is not sufficient to successfully take on the difficult duties that lie ahead for the state premier," he said.
Merkel, who has headed an uneasy "grand coalition" with the centre-left Social Democrats (SPD) since 2005, needs to strike a balance between positioning her conservatives ahead of the 2009 election and holding together a delicate partnership of CDU, CSU and SPD already tested by moves on economic and social reform.
While federal Agriculture and Consumer Affairs Minister Horst Seehofer is widely expected to become CSU leader, there will be a contest for the state premiership.
Alongside Seehofer, Bavarian Interior Minister Joachim Herrmann, state Science Minister Thomas Goppel and head of the CSU's parliamentary party Georg Schmid have expressed an interest in taking over the premiership, said CSU deputies.
Aside from Seehofer, who has a national standing with a spot in Merkel's cabinet, the others are barely known beyond Bavaria.
The new leadership is expected to push the interests of Bavaria more forcefully in Berlin.
The CSU won 43.4 percent on Sunday, down from 60.7 percent in the 2003 state vote, and it lost the absolute majority it had held in the state assembly for nearly half a century.
Bavaria was one of Germany's poorest states in the immediate post-World War Two years, absorbing tens of thousands of refugees from territories ceded to Poland and Czechoslovakia. But its economy grew quickly, electronics and motor cars underpinning traditional agriculture.
Both Beckstein and Huber at first resisted pressure to resign over the election defeat. The CSU is still the largest party in Bavaria by far and will continue to run the state, albeit in a coalition with another party.
The 59-year-old Seehofer lost a bid for the chairmanship of the CSU a year ago after news his mistress had given birth to his child sapped support among the party's Catholic base.