'Political earthquake' in Berlin

Chancellor Gerhard Schroeder's party made strong gains

Germany's ruling Social Democrats are heading for victory in elections for the mayor and regional assembly in Berlin, in what some analysts are describing as a "political earthquake" for the city.

But without an overall majority, a coalition will have to be built - and strategy talks were under way on Monday to discuss whether the city's former communists could get their first share of power since the fall of the Berlin Wall.

Klaus Wowereit wants a change of mentality in Berlin's government

Preliminary results show the left-of-centre SPD increasing its share of the vote to nearly 30%. Its national coalition partners, the Greens, got just over 9% - so even the two parties together cannot build a majority administration.

The conservative Christian Democrats, tainted by allegations of sleaze, saw their support plummet from 40% to under 24% - barely ahead of the ex-communists.

Their mayoral candidate Frank Steffel took the blame for what he described as a "painful defeat".

The former East German communists, the PDS, appeared to have achieved their best result since reunification, with nearly 23%.

Coalition partners

BBC Berlin correspondent Rob Broomby said it was not clear which partners SPD mayor Klaus Wowereit would choose for government.

Both the PDS and the free-market liberal FPD are contenders, after improving their respective shares of the vote substantially.

Gysi said he was ready to join the government

But our correspondent says the support of either would come with a price.

PDS candidate Gregor Gysi says he is ready to govern in a "red-red" coalition, but the idea has shocked victims of the old communist regime.

He said the party had "come further than people thought we could".

Its objections to US military action in Afghanistan proved not to be a vote-loser as expected, but may have bolstered its position in its traditional stronghold in the east.

CDU collapse

Mr Wowereit has governed the city since the collapse of the old grand coalition of both Christian and Social Democrats in June.

CDU candidate Steffel said Munich was his favourite city

The old CDU-led coalition governed the city from 1991 until it was brought down by a multi-million dollar debt burden.

The SPD appears to have benefited from an increasingly bitter and personal campaign.

First, Mr Wowereit announced he was gay, which in such an open-minded city may have helped his profile.

An attempt by Mr Steffel to capitalise on his heterosexuality, however, in a poster showing his photogenic wife, did not help him. Neither did telling Berliners his favourite city was Munich.