BERLIN (AP) — Germany's four biggest parties held a series of bilateral meetings Sunday to further sound out each others' positions before deciding on further steps in forming a government.

The center-left Social Democrats, who finished on top in Germany's national election last month, first met with the fourth-place pro-business Free Democrats before holding talks with the Greens, who came in third.

The latter two had already kicked off the traditional negotiating dance Wednesday, though it is unusual for smaller parties to make the first move.

Sunday's sessions in Berlin — described by some observers as akin to speed dating — were rounded off by a meeting between the Free Democrats and outgoing Chancellor Angela Merkel's center-right Union bloc, which suffered a narrow defeat Sept. 26.

All parties insisted they had held “constructive” talks, but refused to discuss substance so as not to jeopardize the negotiations.

Free Democrats negotiator Volker Wissing acknowledged that there were some “cliffs," though he declined to elaborate.

Olaf Scholz of the Social Democrats, who currently stands the best chance of succeeding Merkel as chancellor after 16 years in office, has said he wants to form a new government before Christmas.

Follow AP’s coverage of Germany’s election at https://apnews.com/hub/germany-election