By Erik Kirschbaum

BERLIN (Reuters) - German President Joachim Gauck expressed support on Friday for Athens' demands for reparations for the Nazi occupation of Greece in World War Two, even though the government in Berlin has repeatedly rejected the claims.

Gauck, who has little real power in Germany but a penchant for defying convention, said in an interview to be published in Saturday's Sueddeutsche Zeitung newspaper that Germany should consider its historical responsibility to Greece.

"We are not only people who are living in this day and age but we're also the descendants of those who left behind a trail of destruction in Europe during World War Two -- in Greece, among other places, where we shamefully knew little about it for so long," Gauck said.

"It's the right thing to do for a history-conscious country like ours to consider what possibilities there might be for reparations."

Greece's demand for 278.7 billion euros ($312 billion) in reparations for the brutal Nazi occupation have mostly fallen on deaf ears, but some legal experts say it may have a case.

Many in Greece blame Germany, their biggest creditor, for the tough austerity measures and record unemployment that have followed from two international bailouts totaling 240 billion euros.

Last month, economy minister and vice-chancellor Sigmar Gabriel called the demand "stupid".

Gabriel said Greece wanted to squeeze some leeway out of its euro zone partners as they set conditions for further financial aid to help Greece avoid bankruptcy.

"And this leeway has absolutely nothing to do with World War Two or reparation payments," he said.

German officials have previously argued that Germany has already honored its obligations, not least with a 115 million deutsche mark payment to Greece in 1960.

Gauck, a former East German pastor, recently caused a stir by condemning the massacre of 1.5 million Armenians by Ottoman Turkish forces a century ago as "genocide", a term that the Berlin government had long rejected. Turkey denies the charge.

(Reporting by Erik Kirschbaum; Editing by Kevin Liffey)