BERLIN (Reuters) - Centrist Armin Laschet positioned himself on Saturday as the man to heal divisions among Angela Merkel’s Christian Democrats after they chose him to lead the party, putting him in pole position to succeed her as Germany’s chancellor. Laschet, premier of the country’s most populous state and the self-styled Merkel continuity candidate, beat arch-conservative Friedrich Merz in a ballot of CDU party delegates. Merkel, Europe’s predominant politician and a consistent winner with German voters since taking office in 2005, has said she will not run for chancellor again in September’s federal election. Since she stepped down as CDU leader in Dec. 2018, the party has struggled to find a suitable successor. In choosing Laschet, premier of the Netherlands-sized state of North Rhine-Westphalia, delegates opted for a candidate more palatable to the left-leaning Greens party, second behind the conservatives in opinion polls and seen as a potential coalition partner come September. But the narrow 521-466 margin of his runoff victory over Merz highlights the challenge that Laschet faces in uniting a conservative bloc that, despite her four successive federal election victories, has never been entirely comfortable with Merkel’s centrist course. In his victory speech, Laschet urged democratic forces to rally against a tide of extremism that had swept through Western nations along with the coronavirus pandemic. “Especially in these days that we are experiencing in the world, the phrase ‘unity, justice and freedom’ is more topical than ever,” he said, quoting the first line of the German national anthem. “Let us fight together for these principles against all those who want to endanger them.” Factions within the CDU accuse Merkel her of having left a vacuum on the party’s right for the far-right Alternative for Germany - and latterly conspiracy theorists questioning the reality of the coronavirus pandemic - to step into, undermining Germany’s democratic order. RELATED COVERAGE NO GUARANTEES Merkel said last year that Laschet, 59, had “the tools” to run for chancellor, the closest she has come to endorsing anyone. But even as leader - binding results of Saturday’s voting are expected on Jan. 22 - Laschet is not guaranteed a run at the chancellorship, as the party could yet nominate someone else. Possible alternative candidates include Health Minister Jens Spahn, credited with a successful response to the coronavirus crisis, and Markus Soeder, the popular premier of Bavaria and the leader of the CSU, the CDU’s sister party in the region. In his candidacy speech, Laschet said the next CDU leader’s task would be to earn trust for both himself and for the party and emphasised his ability to integrate all of its wings. “I keep hearing that you also have to be able to polarise. I say: no, you don’t have to,” he told an empty conventional hall, from which the congress was livestreamed to delegates. “You have to master the tools of centrist politics, the ability to unite.” Soeder said he was looking forward to working with Laschet. “Together we will continue the Union’s success story,” he wrote on Twitter. Slideshow ( 5 images ) The Bavarian has called for the CDU/CSU to decide on its chancellor candidate only after state elections in mid-March, leaving open the possibility he could run if Laschet stumbles. Finance Minister Olaf Scholz wished Laschet luck. “This year will be a challenge for all of us,” tweeted Scholz, who is chancellor candidate for the Social Democrats (SPD), junior partner in Merkel’s ruling coalition. Green Party leaders Annalena Baerbock and Robert Habeck said Laschet must redefine the CDU and set a course to modernise the economy in an environmentally sustainable way. Opinion polls give Merkel’s conservative bloc around 36% of votes, followed by the Greens on around 20% and the SPD on 16%. Slideshow ( 5 images ) Merz, who narrowly lost a 2018 bid for the CDU leadership, told Reuters he had offered Laschet the possibility of joining the current government as economy minister. A spokesman for Merkel said no government reshuffle was planned. Merkel was succeeded in 2018 as party leader by her protegee Annegret Kramp-Karrenbauer, who struggled in the role and said last year she would step down.