French energy firm Electricite de France has reported strong sales in the first half of 2006 thanks to increased demand and a rise in European prices.
EdF and other energy firms have upped their prices
Sales beat forecasts at 30.36bn euros (£20.5bn), up from the 25.19bn euros earned in the same period last year.
Shares closed 6% higher on Friday as analysts think it is increasingly likely that the French government will approve further tariff hikes.
Like its rivals, EDF has upped prices in the face of rising wholesale costs.
"The main reason why the shares rose is because of the hope that EDF will get a tariff increase," said one analyst.
The government is set to reach a decision between 12 and 14 August on whether EDF can up its rates.
Price increases in Germany, France and the UK had all contributed to EDF's growth in sales.
In July, EDF's UK division said its gas prices would rise by 19% and electricity prices would increase by 9.1% from 31 July.
France was recently forced to import 2,000 megawatts of energy as the heatwave that swept across Europe saw a big increase in the use of air conditioning units.
At the time EDF said the squeeze highlighted the need to invest in secure energy supplies.