FRANKFURT - Big European banks are unlikely to merge for the coming months until new capital and liquidity rules become clear, the chief executive of Nordea Bank said on Tuesday.

Right now, it is very difficult to see any deals done by systemic (large) banks, Christian Clausen said on the sidelines of the Euro Finance Week conference.

Regulations were likely to take another 12 months to be adopted and merger activity was likely to pick up once the direction of the new rules became clear, he said.

Once it's clear to everybody what will happen to their own bank and with the other bank, then we are in for quite big activity in this area in Europe, Clausen said, adding that fallout from the new rules could also drive down acquisition prices.

Clausen declined to comment on specific targets, though he said the bank had no geographical or other constraints on potential acquisitions.

Speculation has increased in recent weeks that Nordea could be interested in Swedish peer Swedbank. (Reporting by Jonathan Gould; Editing by David Holmes)