Germany's center-left Social Democratic Party narrowly beat Chancellor Angela Merkel's center-right Christian Democratic Union for the first time since 2005 in Sunday's parliamentary election. But the formation of a coalition government faces many uncertainties and could take months.

The preliminary results announced by Germany's federal election commissioner on Monday morning show that the Social Democrats led by Olaf Scholz took 25.7 percent of the vote, while the alliance of the Christian Democrats and the Christian Social Union, headed by Armin Laschet, received 24.1 percent, its worst result in postwar history and the first time it has secured less than 30 percent of the vote.

Both the Social Democrats and the CDU/CSU alliance have said that they wish to form the next coalition government.

The environmentalist Greens party captured 14.8 percent of the vote to be the third-largest party in the lower house of the parliament, known as the Bundestag, while the pro-business Free Democratic Party got 11.5 percent. The far-right Alternative for Germany obtained 10.3 percent and the Left Party won 4.9 percent.

The results have left open several possibilities for a coalition government. It could still be a grand coalition between the CDU/CSU alliance and the Social Democrats, which has governed Germany since 2013. But since they have both talked about building their own coalition, Germany might see a three-way coalition at the federal level for the first time since the 1960s.

The two parties are expected to court the Greens and the Free Democrats to form a coalition. Both Scholz and Laschet said that they hope coalition talks would be accomplished by Christmas.

The Bundestag will hold an election for a new chancellor to replace Merkel only after the formation of a coalition government. It will be up to German President Frank-Walter Steinmeier to pick the candidate, which is often from the senior coalition partner.

Scholz, the current vice-chancellor and finance minister in Merkel's coalition government, said on Sunday night that the vote gave the Social Democrats "a clear mandate to ensure now that we put together a good pragmatic government for Germany" with him as the chancellor.

Laschet, governor of Germany's most populous state of North Rhine-Westphalia, said on Sunday night that "we will do everything we can to form a government" under the CDU/CSU alliance's leadership.

In 2017, it took almost six months for Merkel to form a coalition, the longest in German history, after the Free Democrats abruptly quit the talks which also included the CDU/CSU alliance and the Greens.

Talks between the Greens, who traditionally favor the Social Democrats, and the Free Democrats, who traditionally prefer the Christian Democrat-led alliance, are considered critical in forming a coalition.

While the Greens had their best performance this time, they had much higher expectations before the elections. Party leader Annalena Baerbock said that "the climate crisis... is the leading issue of the next government, and that is for us the basis for any talks... even if we aren't totally satisfied with our result".

Free Democrats leader Christian Lindner said after that election that "it might be advisable...that the Greens and Free Democrats first speak to each other to structure everything that follows" since about 75 percent of Germans "didn't vote for the next chancellor's party".

The German Constitution does not specify that the chancellor has to come from the largest parliamentary group, but from the ruling coalition.

A YouGov poll released on Sunday night shows that about 43 percent of Germans say that Scholz should become the next chancellor.

Ding Chun, director of the Center for European Studies at Fudan University, described Scholz as a typical German politician with his "rational, pragmatic and calm" style.

Ding hosted a speech made by Scholz at Fudan University in 2015 when Scholz was the mayor of Hamburg, a sister city of Shanghai.

Speaking at the United Nations General Assembly on Friday, German President Steinmeier said that the world could depend on Germany whatever happens in the elections.

"I would like to assure you, also after this election, Germany remains a country that is aware of its international responsibility and shoulders it," he said.