SCOTTISH Power is cutting domestic gas prices by 4.8 per cent.
The firm said the changes will see the average annual gas bill on a standard tariff reduced by £33.
The move comes a day after a British Gas announced a five per cent reduction, with Eon last week cutting gas prices by 3.5 per cent.
Energy firms have been under pressure from politicians and regulators to pass on the fall in wholesale gas prices to consumers.
Scottish Power's announcement will affect 1.1 million customers on standard or variable rates, but not those on fixed tariffs.
Neil Clitheroe, Scottish Power's head of retail and generation, said: "This decision has been made to benefit our customers and keep our prices competitive."
The changes are expected to put pressure on rivals SSE, NPower and EDF to do the same.
An SSE spokesman, said: "We're continually looking at our prices and costs and when we announced our price freeze to 2016, we said we'd cut prices if we can.
"If we can lower prices or extend our freeze, we will."
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