E.ON UK said Tuesday it was cutting its retail gas prices for its UK Powergen customers by 16% and its retail electricity prices by 5%, effective from April 30th, 2007. The move is a response to recently announced price cuts by Centrica’s British Gas subsidiary and RWE-Npower.  E.ON UK said that Powergen would be cheaper than British Gas when the new prices become effective. In an early response to British Gas’s price cuts, E.ON UK had earlier launched some new tariffs available on demand offering reduced prices for its customers. But E.ON UK did not initially cut its standard tariffs.  The level of British Gas’s price cuts is believed to have taken some of that company’s rivals by surprise, so it has taken them time to catch up. EDF Energy, Scottish Power and Scottish and Southern Energy, the other three of the big six retailers have not yet announced price cuts, although SSE has said it will “blow British Gas out of the water” when it does.  Customers on Powergen’s Age Concern tariff and StayWarm scheme for the over-60s will also see the impact of this decrease.