Axel Weber, chairman of Swiss bank UBS, raised the possibility of an industry-wide settlement for the rest of the banks involved in the scandal at a meeting of top bankers in Davos earlier this month, sources familiar with the matter told Reuters.

UBS and Britain's Barclays have already reached settlements with regulators.

"I can confirm there were unofficial discussions (in Davos)," Jain said on the sidelines of a press conference, adding the talks were very informal and not at a very advanced stage.

Jain said that banks had different interests and it was therefore unclear if any agreement would be reached.

He said an industry-wide settlement might help banks resolve potential civil suits which could follow criminal and regulatory investigations.

"A Libor settlement would make sense for civil suits," he said.

U.S., British and other regulators are investigating more than a dozen global banks over manipulating the London interbank offered rate (Libor), a benchmark used for trillions of dollars of financial instruments ranging from home loans to complex derivative products.

For banks, a collective agreement would reduce the risk that any individual bank will be singled out and face a particular backlash. A group agreement is difficult to attain but has been done in the past in the tobacco industry, for example.

The main obstacles facing a group settlement are likely to be a hesitancy on the part of the investment banks to work together in the fevered atmosphere surrounding the Libor investigations and the large number of regulators involved in investigating cases.

Deutsche Bank has increased its litigation reserves to 1.8 billion euros ($2.4 billion) from 800 million euros, some of which is related to the Libor probe.

In addition, 2 billion euros of contingent liabilities remain, the bank said, referring to possible losses over and above existing legal provisions.

Money for lawsuits has so far only been set aside for possible regulatory or criminal cases, but not for potential civil suits.

(Reporting by Arno Schuetze, Edward Taylor, Philipp Halstrick; Editing by Mark Potter)