Energy firm E.ON said today that it was cutting its standard gas tariff by 6% from the end of this month.

The firm said the reduction would affect 1.9m customers, although those on fixed or contract deals will not benefit.

E.ON said the average annual bill would be £42 lower for those paying by direct debit.

E.ON has about 5.5m customers in the UK and the company said many of its customers would not be affected by the cuts as they either received only electricity, or were on fixed-rate deals.

The move is the third in the recent gas price cuts across the industry amid falling wholesale prices.

But consumer groups have criticised the sector for not moving faster to cut prices in the face of a bitterly cold winter.

E.ON said its standard gas reduction would become effective from March 31.

The firm cut electricity by 9% in March last year and gas by 3.3% in July.

Today’s reduction follows last month’s 7% cut in British Gas’s average standard gas tariff and a 4% reduction from Scottish & Southern Energy.

Graham Bartlett, managing director of E.ON’s retail business, said: “We’ve been very aware of the effect of both the recession and the exceptionally cold winter on our customers, especially those most in need, so we are pleased to see the opportunity to now reduce prices.

“The fall in current wholesale prices is only part of the pricing story as our customers are using gas bought over a number of years at much higher prices than today.”

The firm has also altered its WarmAssist product from March 1, aimed at the most vulnerable, where alongside the standard gas cut, electricity prices were reduced 5%.