NEW YORK (Reuters) - Ultra-low European Central Bank interest rates could lead to excessive risk-taking but it is up to supervisors to mitigate these risks as ECB policy is clearly doing the job intended, Governing Council member Philip Lane said on Tuesday.

Lane, the governor of the Central Bank of Ireland, said low interest rates posed the dual risk of creating real estate bubbles and, if sustained too long, contributing to economic stagnation.

"A possible side-effect of the low interest rate environment is that it may induce some asset and real estate market participants to engage in excessive risk-taking," Lane said in a speech at New York University, according to a transcript.

The risk of real estate bubbles is mitigated by the ECB's Single Supervisory Mechanism's regulation of the lending practices of the 129 most important European banks and by the actions of national macroprudential authorities in each EU state. National fiscal policies can also play a role in mitigating the financial cycle, he said.

The other main risk of ECB policy is a "'low for long' stagnation scenario," but acting decisively to lift inflation to its target level is the best way to avoid this, Lane said.

"Forceful accommodative monetary policy in the short run is the best method to ensure that policy rates do not stay low for longer than is necessary," he said.

(Writing by Conor Humphries; Editing by Catherine Evans)