British Gas owner Centrica has predicted annual profits may beat forecasts after price cuts brought it 900,000 new customers.
Most energy suppliers have followed British Gas and cut prices
British Gas has cut gas and electricity prices twice so far this year because of lower wholesale charges.
In 2006, the company lost customers as it raised tariffs, blaming an increase in wholesale prices.
All energy suppliers have come under pressure from their regulator to match the falls in wholesale energy prices.
If wholesale prices remain at current levels, Centrica predicted it was on course to beat current profit forecasts.
British Gas currently has 15.8m domestic customers. However, this is still well below the number it had before price rises began prompting people to switch energy providers.
The statements were made ahead of Centrica's annual general meeting.
News that British Gas had signed up almost a million new customers came as a Uswitch survey revealed the group came bottom of a customer satisfaction survey.
However, British Gas dubbed the poll "misleading", as it was carried out before its latest price cuts in April.