Too Early to Decide How ECB Should Respond to Brexit?

AIX-EN-PROVENCE, France--European Central Bank executive board member Beno�t Coeur� said Sunday it was too early to decide how to respond to Britain's vote to leave the European Union given the current economic and political uncertainty.

The comments, at a the Rencontres �conomiques conference in South of France, indicate that the ECB will take time to gauge how eurozone banks and businesses are reacting to the shock before unleashing any fresh stimulus measures. Economists have been speculating that the ECB could act as soon as September to bolster the bloc's economy.

"There are things that we can do but it is too early to decide whether Brexit calls for action from the central bank," Mr. Coeur� said.

Last week's surprise referendum result sent global equity markets sprawling, with European bank stocks coming under particular pressure. The pound has tumbled against the dollar and other currencies, and the euro has also lost ground.

Mr. Coeur� urged the U.K. and the European Union to work together to clarify the time frame and exact terms of Britain's exit, while French economy minister Emmanuel Macron, speaking on the sidelines of the conference, called for a referendum across the EU on a new road map for bloc.

"Rather than national debates, let's organize a referendum across Europe to ensure that citizens agree with the new road map," said Mr. Macron.

Also at the conference was Bank of France Governor Fran�ois Villeroy de Galhau, who warned that the city of London was at risk of losing its EU "passport" and clearing houses, unless it can quickly find an agreement with the EU.

The EU passport enables a firm established in one EU country to operate in the others without having to undergo separate regulatory oversight.

Many U.S. and other non-European institutions run their EU operations out of London. Following the British vote on June 23 to leave the union, it is believed some banks may move at least part of their operations to another country to secure their EU passport.

Mr. Villeroy de Galhau, who also sits on the European Central Bank governing council, said it was "desirable" for U.K. to secure access to the single market in its exits talks.

"If such an agreement isn't found, there will be no financial passport for the city, and the clearing houses won't stay in the U.K.," Mr. Villeroy de Galhau said.

In the short term, the U.K. also faces a risk of inflation and economic recession, he added.

Write to Noemie Bisserbe at noemie.bisserbe@wsj.com