Berlin mayor confident he can stop Greens' surge
* Mayor aims to beat back Greens' rally
* SPD now ahead of Greens in polls
BERLIN, Aug 4 (Reuters) - Berlin mayor Klaus Wowereit said on Thursday he was confident he could put a stop to the surge of the Germany's Greens party and win a third term leading the country's biggest city-state in a September election.
The Greens have surged to record highs in opinion polls in the last year, boosted in part by the nuclear disaster in Japan, and rocked the political landscape by snatching control of the country's wealthiest state, Baden-Wuerttemberg, from Chancellor Angela Merkel's CDU party in a March election.
Wowereit, a leader in the centre-left Social Democrats (SPD), said on Thursday that his party had repelled the Greens' rise and that all polling institutes now showed the SPD comfortably ahead of the pro-environment party.
"The trend for the Greens is down," he told the Foreign Press Association (VAP) in the week the campaign kicked off for the Sept. 18 election.
The Greens had been leading the SPD in Berlin by 2 to 3 points in some polls as late as May but since June the SPD has been 4 to 6 points ahead of the Greens.
Polls show the SPD are in front now with 30 percent to about 24 percent for the Greens and 20 percent for Merkel's conservative Christian Democrats (CDU). Berlin is one of Germany's 16 federal states.
"It's only the start of the election campaign but I've got every reason to be content right now," said Wowereit, whose SPD is hoping his re-election in Berlin in September will give the party a boost ahead of the 2013 federal election.
National polls show the SPD and Greens running neck-and-neck and the two centre-left parties are far ahead of Merkel's centre-right coalition. Another drubbing for the CDU in Berlin is likely to lead to growing citicism of Merkel.
Wowereit is a Berlin native who became a national celebrity for coming out as gay a decade ago as tabloids were planning to expose his sexuality. His Greens rival is not a native of the city.
He dismissed suggestions that he had grown weary in office after 10 years of running the city, the poorest big city in Germany burdened by heavy debts and a high unemployment rate.
"Sure there was talk in the public about whether I might be fatigued or fed up," he said. "But I haven't reached that yet.
"If I were so depressed even before getting to work in the morning then I wouldn't run again," he said. "I've asked myself the questions (about fatigue) and the answer is: I'm motivated to run and want another five years. I feel the wind at my back."
Wowereit had appeared to be in a fight for his political life earlier this year after the Greens emerged on top of the coalition in Baden-Wuerttemberg and polls showed the Greens with a heavyweight candidate, Renate Kuenast, just ahead in Berlin.
Wowereit, who has ruled for the last 10 years with the Left party, said it was clear voters wanted a left-leaning coalition. He said he was open to a coalition with the Greens or Left party.
Asked why he remained so popular after 10 years as mayor of the city, he said in his native Berlin accent: "Because Wowereit and the city, it's a good fit."
(Editing by Elizabeth Fullerton)