* Polls show Greens could capture powerful state
* Greens-led government would make history in Germany
By Dave Graham and Hans-Edzard Busemann
BERLIN, Sept 16 (Reuters) - Germany's Greens, who are riding a wave of record support, may take control of a state government for the first time next year, co-leader Cem Oezdemir said on Thursday, and deal a severe blow to Chancellor Angela Merkel.
Oezdemir told Reuters that surveys showed the centre-left Greens and Social Democrats (SPD) could oust Merkel's conservatives from the southwestern state of Baden-Wuerttemberg, one of Germany's biggest, in a March election.
"We now have poll results that show it could be enough (to rule) together with the SPD," Oezdemir, 44, said in an interview.
A survey by pollster Infratest Dimap published last week showed 27 percent of Baden-Wuerttemberg voters backing the Greens, and 21 percent the SPD, which would suffice for a majority -- and turn the tables on the traditionally bigger SPD.
"As far as the question of the state premier goes, it's quite simple. The party ahead at the end is usually the one to have the state premier," he said. "But we're not that far yet."
Merkel's Christian Democrats (CDU) have ruled the state, which is home to carmaker Daimler and software giant SAP, since 1953. With a population of nearly 11 million, the state has an economy the size of Poland's.
The Infratest poll showed the CDU securing 35 percent of the vote in Baden-Wuerttemberg and their Free Democrat (FDP) allies 5 percent -- the minimum needed to enter parliament in Germany.
If the Greens took the reins in Baden-Wuerttemberg, it would be a watershed for an environmentalist party founded in 1980 that served as junior partner in the national administration of SPD chancellor Gerhard Schroeder between 1998 and 2005.
It would hit 56-year-old Merkel, whose authority has been weakened by internal rebellions, a state election defeat in May and infighting in her ruling federal coalition with the pro-business FDP in Berlin.
The Greens have never served as senior partner in any of the 16 state governments in Germany, where coalitions are the norm.
The party has also been ahead in polls for the state of Berlin, which will elect a new parliament next September.
Oezdemir, a local of Baden-Wuerttemberg born to Turkish immigrants, said the party was keeping its feet on the ground about the prospects of playing a bigger role nationally.
"We're certainly not going to put forward a candidate for chancellor," he said looking to the next federal vote in 2013. "The trend is good, but there's still a lot to do."
Nationally, the Greens are also breathing down the SPD's neck. A Forsa poll this week put support for the party at a record 22 percent in Germany, just behind the SPD on 24 percent.
The SPD used to treat the Greens "like children", Oezdemir said. "We're competitors, we've nothing to give away," he said.
Support for the Greens in Baden-Wuerttemberg has been boosted by their opposition to a multi-billion euro plan to rebuild the railway station of state capital Stuttgart -- and by their forthright stance against nuclear power in Germany.
Merkel's coalition agreed this month on a plan, yet to be approved by parliament, to extend the lifespans of Germany's nuclear power stations, despite public scepticism.
Though Oezdemir made plain his party would sooner form a government with the SPD in Baden-Wuerttemberg, he did not categorically rule out working with the CDU, with whom the Greens have formed alliances in two of Germany's states.
However, Baden-Wuerttemberg's CDU premier Stefan Mappus has been a vocal supporter of extending nuclear plants' lifespans, making a partnership unlikely with the Greens, who were instrumental in agreeing a shutdown of nuclear plants by 2021 under Schroeder.
"The nuclear pullout isn't negotiable," Oezdemir said. (Additional reporting by Erik Kirschbaum; editing by David Stamp)
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