BERLIN — German leaders met Thursday night for more than two hours in their latest effort to end the country’s political deadlock since inconclusive September elections and the collapse of coalition talks led by Chancellor Angela Merkel nearly two weeks ago.

This time Ms. Merkel was returning to her old coalition partners, the center-left Social Democrats, to explore whether they could overcome past differences and more recent tensions to open negotiations on a new government together.

On Thursday evening she met with Martin Schulz, the Social Democratic Party’s leader, at the presidential palace, along with the head of the Bavarian wing of her conservative bloc, as part of efforts by the German president to avoid a snap election.

After more than two hours of closed-door meetings, the leaders left the presidential palace without making any statements. They had mutually agreed not to divulge any details until they had an opportunity to inform their respective parties of the outcome on Friday, in part as a result of criticism that the previous talks failed because too many details were made public.