Centrica has warned that British Gas customers face price rises throughout 2011. A statement said “In the UK, the forward wholesale prices of gas and power for delivery in winter 2011/12 are currently around 25% higher than prices last winter, with end-user prices yet to reflect this higher wholesale market price environment,”Centrica also warned of the impact of a rise in energy taxes. Last month, the government unexpectedly raised a supplementary tax charge on North Sea oil and gas producers from 20% to 32%. “We continue to expect growth in our 2011 group earnings but at a more modest rate than anticipated at the time of our last results announcement as upstream profits have become more highly taxed,” the company said. “We no longer expect to maintain the previously projected high levels of investment in the UK,” it said.