The Bord Gáis Energy Index rose 3% last month as wholesale natural gas and electricity prices increased by 21% and 17% respectively.
However, these increases were offset by a 5% fall in Brent crude oil prices as a new wave of oil supply from the US is flooding the market amid weak demand.
Bord Gáis said the falling price has been described as a "collapse" with oil sellers having to work harder in a market "awash with oil".
The company said the monthly increase in wholesale UK natural gas prices was due to the frequently under supplied system because of maintenance issues, while cooler temperatures towards the end of the month also had an effect on prices.
Irish electricity prices also rose last month mainly to due to the rising wholesale natural gas prices in the UK.
Bord Gáis pointed out that as gas generation electricity dominates the generation mix on the island of Ireland, the price of imported UK gas has a major influence on electricity prices.
The low monthly production volume from the country's fleet of wind farms - due to the clement weather conditions and low wind speeds - also hit prices.
Meanwhile, the coal element of today's index fell by 2% due to thin demand from European buyers amid ample levels of supply.
John Heffernan, a gas and power trader at Bord Gáis, said it is expected that the dominant issue for the coming winter will be the security of Europe's gas supplies that are still threatened by the failure to reach an interim deal on the gas row between Russia and Ukraine.
He said that due to the mild winter last year, the UK has a large volume of gas in storage.
"These reserves and a mild start to this winter have the potential to somewhat curtail significant price increases over the first half of the winter if the dispute results in a disruption of gas flows to Western Europe as a result of Ukraine siphoning off gas destined for Western Europe in order to meet domestic demand," Mr Heffernan said.