BERLIN (AP) -- Chancellor Angela Merkel was strongly favored to win a third term at the helm of Europe's biggest economy as Germans voted in a national election Sunday, but the popular conservative's hopes of governing with center-right allies for another four years were in the balance.
Nearly 62 million people were eligible to elect the lower house of Parliament, which in turn chooses the chancellor.
Merkel's Christian Democratic Union and its Bavaria-only sister, the Christian Social Union, appeared likely to emerge as the strongest force and fend off a challenge from center-left rival Peer Steinbrueck. But beyond that, things may get more complicated.
Early indications pointed to a higher turnout than four years ago, election officials said -- with 41.4 percent of eligible voters casting their ballots by 2 p.m. (1200 GMT), four hours before polling stations closed. That compared with 36.1 at the same point in 2009. Experts say a higher turnout could help Steinbrueck's party.
No single party has won a majority in Germany in more than 50 years. Merkel would like to continue governing with her partner of choice, the pro-business Free Democratic Party -- but polls have shown support for the smaller party fading from nearly 15 percent in the 2009 election to around the 5 percent needed to keep any seats in Parliament.
Merkel pleaded Saturday for "a strong mandate so that I can serve Germany for another four years, make policies for ... a strong Germany, for a country that is respected in Europe, that works for Europe; a country that stands up for its interests in the world, but is a friend of many nations."
Her party has rebuffed calls from leading Free Democrats for Merkel supporters to back them, saying it has no votes to spare. Polls showed the coalition in a dead heat with a combination of Steinbrueck's Social Democrats, their Green allies and the hard-line Left Party -- but the two center-left parties have ruled out an alliance with the latter.
If her current coalition falls short of a parliamentary majority, the likeliest outcome is a switch to a Merkel-led "grand coalition" of her conservatives with the Social Democrats, the same combination of traditional rivals that ran Germany from 2005 to 2009 in Merkel's first term.
That's unlikely to produce a radical change in policies. However, it could signal subtle shifts, perhaps a greater emphasis on bolstering economic growth over the austerity that Germany has insisted on in exchange for bailing out economically weak European countries such as Greece.
Final results are due within hours of polls closing at 6 p.m. (1600 GMT). But with margins so close, the country could still face weeks of horse-trading before a clear picture of the new government emerges.
Merkel calls her current coalition "the most successful government since reunification" 23 years ago. She points to the robust economy and unemployment which, at 6.8 percent, is very low for Germany and far below that of many other European countries.
Polls gave Merkel popularity ratings of about 70 percent. The sky-high popularity doesn't extend to her coalition, which has bickered frequently over issues ranging from tax cuts to privacy laws. The Free Democrats have taken much of the blame.
"They said it was a marriage of love -- that was how they ran in 2009 -- and then the divorce lawyer spent the whole time running along the sidelines," Steinbrueck said at a rally in Frankfurt on Saturday.
Steinbrueck's platform stresses the importance of narrowing the gap between rich and poor. He wants to introduce a national minimum wage and raise income tax for top earners. Merkel and the Free Democrats contend that both measures could backfire and hurt the economy.
A new party, Alternative for Germany, which calls for an "orderly breakup" of the euro currency zone and appeals to socially conservative voters, could sap votes from the governing parties and complicate Sunday's outcome. Polls suggested that it could enter Parliament -- but Merkel and others are ruling out working with it.
"Stabilizing the euro is not just a good thing for Europe, it is in the elementary interests of Germany," Merkel said Saturday. "It secures jobs and it secures our prosperity."
She said that her course of helping Europe's strugglers in exchange for budget discipline and reforms "must be continued."
A euro breakup "would set European unification back 20 to 30 years" and ruin German businesses, said Steinbrueck, whose party backed Merkel's eurozone policies in Parliament but criticized her for over-emphasizing austerity.
Germany's government, he said, has "a clear European responsibility to hold this continent together."
An opinion poll published Sunday by the weekly Bild am Sonntag put support for Merkel's conservatives at 39 percent. Her allies the Free Democrats were at 6 percent.
Steinbrueck's Social Democrats would receive 26 percent of the vote, according to the poll. The Greens and the Left Party each came in at 9 percent.
The survey of 2,047 voters was conducted by the Emnid research institute from Sept. 15-20.