Hannibal Hanschke / Reuters German Chancellor Angela Merkel addresses a news conference, to announce that she will run again for the Chancellorship.

BERLIN, Nov 20 (Reuters) - Angela Merkel announced on Sunday she wants to run for a fourth term as German chancellor in next year’s election, a sign of stability after Britain’s vote to leave the European Union and the election of Donald Trump as the next U.S. president.

Despite a voter backlash over her open-door migrant policy, the 62-year old conservative said she would stand again in the September election, ending months of speculation over her decision.

“I thought about this for an endlessly long time. The decision (to run) for a fourth term is - after 11 years in office - anything but trivial,” Merkel told a news conference after a meeting of senior members of her conservative Christian Democrat (CDU) party convened to prepare for the election.

Some 55 percent of Germans want Merkel, Germany’s eighth chancellor since World War Two, to serve a fourth term, with 39 percent against, an Emnid poll showed on Sunday, highlighting that despite setbacks, she is still an electoral asset.

Merkel has steered Europe’s biggest economy through the financial crisis and euro zone debt crisis and has won respect internationally, for example with her efforts to help solve the conflict in Ukraine. U.S. President Barack Obama last week described her as an “outstanding” ally.

With Trump’s victory in the United States and the rise in support for right-wing parties in several European states, some commentators see Merkel as a bastion of Western liberal values.

“Angela Merkel is the answer to the populism of this time. She is, as it were, the anti-Trump,” party ally Stanislaw Tillich, premier of the state of Saxony, told the RND newspaper group, adding she stood for reliability and predictability.

However, her decision last year to open Germany’s borders to around 900,000 migrants, mostly from war zones in the Middle East, angered many voters at home and dented her ratings.

Her party has slumped in regional elections in the last year while support for the anti-immigrant Alternative for Germany (AfD) has swelled.

In September, after a heavy defeat for the CDU in a Berlin state election, a humbled Merkel surprised the country by saying she wished she could turn the clock back on the migrant crisis, though she stopped short of saying her policy was a mistake.

Kevin Lamarque / Reuters U.S. President Barack Obama speaks during a joint news conference with German Chancellor Angela Merkel in Berlin, Germany, November 17, 2016.

BIG TASKS AHEAD

If re-elected, her responsibilities will range from helping lead talks with Britain on its withdrawal from the EU, soothing tense relations with Turkey, a crucial partner in the migrant crisis, and developing a relationship with Trump.

Domestically, her biggest challenge will probably be managing the integration of refugees in an increasingly divided society and keeping Europe’s powerhouse economy on track.

An Emnid poll on Sunday put Merkel’s conservative bloc down one point at 33 percent, nine points ahead of her nearest rivals, the Social Democrats (SPD), with whom she shares power.

In a system where coalition governments are the norm, many pollsters see another ‘grand coalition’ as the most likely option after the election, although the rise of the AfD makes coalition arithmetic more complicated.

The SPD has not decided whether its chairman Sigmar Gabriel, Vice Chancellor and Economy Minister, will run against Merkel.

One of the SPD’s deputy leaders, Ralf Stegner, said it would be a mistake to underestimate Merkel but that the “myth of invincibility” was over.

Merkel, who grew up in Communist East Germany, is a physicist who only became involved in politics after the fall of the Berlin Wall in 1989. She is seen as a talented negotiator but has also shown a ruthless streak.

A Protestant woman in a mainly Catholic and male-dominated party, at least when she became its leader in 2000, Merkel never built up a regional power base but over the years she has sidelined her main male rivals and has no obvious successor.

She still requires the official backing of her Christian Social Union (CSU) allies in Bavaria, who have fiercely criticized her open-door migrant policy. CSU head Horst Seehofer welcomed her decision on Sunday.

“We now want the trust of the population for another four years and therefore it is good that we have clarity,” he said.

Germany has no limit on the number of terms a chancellor can serve. By standing again, Merkel, who said she wanted to serve the full fourth term, could end up matching the 16 years in office of her former mentor, Helmut Kohl. It was Merkel herself who broke with Kohl and told her party in 1999, in the midst of a funding scandal, that it should move on without him.