UK's EDF Energy raises prices for second time this year

* Bills to rise by about 78 pounds on average

* Fifth company to increase prices this year

* Government to publish consumer green paper in the spring (Adds detail, context)

LONDON, April 12 (Reuters) - EDF Energy will raise its dual-fuel prices by 7.2 percent from June 21, the company said on Wednesday, increasing its prices for the second time this year.

The move comes against the backdrop of a British retail energy market coming under increasing scrutiny after five of the country's bix six suppliers announced significant price rises for this year.

The government has said it is prepared to act and has said that a consumer green paper that could include proposals for the energy market will be published in the spring.

EDF Energy, the British arm of French utility EDF (Paris: FR0010242511 - news) , said the latest price rise will add about 78 pounds ($97.51) on average to bills for customers supplied with both gas and electricity.

The increase comes on top of a 1.2 percent rise in dual-fuel prices that came into effect on March 1.

EDF Energy Chief Executive Vincent de Rivaz said the industry is facing significant cost increases but that the company needs to make a fair margin in supplying customers.

"This fair margin allows us to invest for the long term, in particular in good service, innovation and smart metering," he said.

The British government wants every home in the country to have a smart meter by 2020, providing households with real-time data on energy use and costs.

Energy suppliers need to supply the meters, with customers ultimately covering the cost through their bills, though the government says that smart meters and costs such as renewable subsidies account for only a small portion of consumers' bills.

EDF Energy said that about 55 percent of its customers will be unaffected by the price rise because they have fixed-term tariffs.

E.ON UK, part of German power utility E.ON, Innogy's Npower, Iberdrola (Amsterdam: ID6.AS - news) -owned Scottish Power and SSE (LSE: SSE.L - news) have already announced price rises. Centrica (Frankfurt: A0DK6K - news) 's British Gas said that it would freeze prices until August. ($1 = 0.7999 pounds) (Reporting by Susanna Twidale; Editing by David Goodman)