FRANKFURT (Reuters) -UniCredit executives had conversations with top German government officials, including from the chancellery and the finance ministry, in the months before buying part of the state's stake in Commerzbank, according to parliamentary documents seen by Reuters.

The details of the meetings are presented in a government response to Matthias Hauer, a German lawmaker, and are the fullest account yet of contact between Germany and UniCredit before the Italian bank swooped to buy a large stake in Commerzbank. The German government has said it was surprised by UniCredit's move.

UniCredit has since pressed for a possible tie-up in what would be the most ambitious attempt yet at a pan-European bank merger, but it faces considerable political hurdles in Germany ahead of national elections.

Florian Toncar, the state secretary in charge of the stake sale, spoke with Marion Hoellinger, the head of UniCredit's German arm, on Sept. 4 about a government agency announcement on the stake sale and again on Sept. 10, the document showed.

Chairman Pier Carlo Padoan met with Joerg Kukies, a top official in the German chancellery, on the sidelines of a conference in Paris on May 16, according to the government's answer, that also flagged two further exchanges with chancellery officials, on June 7 and May 30.

While the document sheds light on various meetings, it offers few details of the content of the discussions.

Hauer, a Christian Democrat lawmaker, said the answer showed a "lively exchange" between the German government and the Italian bank, urging a further inquiry into how the government had sold the entire stake for sale to UniCredit rather than a number of investors.

"The German government ... make out as if they have nothing to do with the chaos at Commerzbank. But they caused it," he said.

UniCredit declined to comment. Germany's finance ministry didn't immediately respond to a request for comment.

The German government became the top shareholder in Commerzbank after a bailout in the global financial crisis more than a decade ago.