The firm said that the reduction would save consumers an average of £25 a year.
Some 1.8 million E.ON customers will benefit from the reduction in the cost of gas.
The move comes three months after the firm slashed nine per cent from its standard electricity tariff.
Announcing the cut in gas prices, E.ON said it was committed to "offering competitive prices at all times and delivering on our promises" news which may be of interest to people switching tariffs or comparing energy prices online.
Earlier this year, E.ON said it would spend £6.9 million fitting carbon capture technology at its Kingsnorth power plant something it hopes will reduce the cost of electricity for its customers.
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