"If (inter-bank lending) transactions were to occur at higher rates than before, then we may see upward pressure on certain money market rates," de Guindos said.

"At this stage, we see very little evidence of this being priced in by the market, but the ECB will continue to actively monitor conditions in the money market," he added.

(Reporting By Francesco Canepa; Editing by Balazs Koranyi)