PARIS, March 16 (Reuters) - France said on Wednesday that G7 finance ministers and central bankers would discuss the economic impact of Japan's earthquake, including possible measures to calm financial markets. A government source said the discussion would likely take place by conference call before the end of the week. France, which chairs both the G8 group of industrialised nations and the G20 club of rich and developing countries, also said it would propose a G20 ministerial meeting on future options for the energy sector after Japan's nuclear crisis. "We need to be at the disposal of our Japanese friends on monetary matters," Finance Minister Christine Lagarde said after the government's weekly cabinet meeting. "I have asked for a meeting of G7 finance ministers and central bankers so that we can see in what way we can take part in their debt issues and how we can react on a financial level," she said. The government source said the discussions would involve a broad look at the economic implications of the crisis, including its impact on economic growth and energy supply and its effect on the financial markets. http://www.cnbc.com/id/42107454