German President Christian Wulff has resigned in a scandal over political favors, according to news reports on Friday.

In a curt five-minute statement at the Bellevue presidential palace, Wulff said he had lost the trust of the German people, making it impossible to continue in a role that is meant to serve as a moral compass for the nation, Reuters reported.

Wulff's resignation from the ceremonial post is a further blow to the already beleaguered Chancellor Angela Merkel, who is struggling to contain the euro zone crisis.

 It is no longer possible for me to exercise the office of president at home and abroad as required, Wulff said, standing next to his wife, Bettina.

The resignation forced Merkel to cancel her scheduled trip to Rome for talks with Italian Prime Minister Mario Monti.

On Thursday, state prosecutors in Hanover asked parliament to end Wulff's legal immunity as they opened an investigation into allegations he had accepted favors.

Wulff is the second German President to step down in two years. His predecessor, former International Monetary Fund chief Horst Koehler, resigned unexpectedly in 2010 after coming under fire for comments he made about the German mission in Afghanistan.

Merkel, who hand-picked Wulff for the presidential position, now has the divisive and distracting task of choosing a successor at a time of great concern about the Greek debt crisis.

This won't be without consequences for Merkel, her reputation will suffer from it, said Gerd Langguth, political scientist at Bonn University who spoke to Reuters.

She has a good ratings in opinion polls at the moment but what effects it will have on her depends who she names as a new candidate and whether they are convincing or not. If not, she could have problems, he added.

A possible successor is Joachim Gauck, an anti-communist human-rights activist in East Germany who ran against Wulff in 2010 and embarrassed Merkel by forcing the election into a third round.

Other potential candidates include Defense Minister Thomas de Maiziere, Labor Minister Ursula von der Leyen and possibly Finance Minister Wolfgang Schaeuble, though shifting him to Bellevue palace would leave a gaping hole in Merkel's cabinet in the midst of the euro zone sovereign debt crisis.