TRENTO, Italy (Reuters) - Britain's exit from the European Union would likely trigger turmoil on financial markets prompting the European Central Bank to act, Governing Council Member Francois Villeroy de Galhau said on Saturday.

Villeroy de Galhau told an economic conference in Italy he hoped Brits would vote to remain within the EU this month. An exit would likely trigger a flight-to-quality among investors, lifting risk premia on lower-rated euro zone issuers' debt.

Central banks would have to step in to counter turmoil and the euro zone would need to speed up its integration efforts, he said.

(Reporting by Valentina Za; editing by Agnieszka Flak)