The government and private companies are stepping up efforts to assess the potential impact of Britain leaving the European Union as London formally notified Brussels of its withdrawal from the bloc.

"There will be significant impact on businesses," Economy, Trade and Industry Minister Hiroshige Seko said at a meeting Wednesday with executives of major companies. He suggested Tokyo will call for efforts by the British government to mitigate such an impact.

"We may need to reconsider our business in Europe, which has largely depended on Britain," a participant from a large manufacturer said after the meeting,