Households and businesses have been warned by Bord Gáis of higher energy costs during the autumn and winter months ahead.
The warning was issued in a routine monthly report on wholesale fuel prices on international markets.
The company said consumers can expect higher electricity costs because natural gas, a key raw material in producing electricity, is set to become more expensive.
Natural gas prices are based on oil prices from six months earlier.
Oil prices were over $100 a barrel in the first six months of the year, which could filter through to billing charges for electricity in October.
The monthly report also finds that the wholesale price of oil, coal and electricity fell in May from a 31-month high because of a global sell-off in commodities associated with fears about the health of the US economy.
