LONDON British spot gas prices fell to their lowest in two weeks on Monday, as unseasonably mild weather capped demand.
Gas for within-day delivery fell 1.00 pence to 69.50 pence per therm, while the day-ahead contract slipped 0.95 pence below Friday's closing price to a two-week low of 69.40 pence.
Temperatures in Britain were some 3 degrees Celsius above seasonal norms, pushing gas demand to around 10 percent below levels usually seen at this time of the year, National Grid data showed.
Britain's gas network was oversupplied by 7.3 million cubic metres (mcm) on Monday morning. Demand was forecast at 264.9 mcm while supply was at 272.2 mcm/day.
"The market remains relatively loose due to soft demand and strong imports through Langeled," according to an analyst for Thomson Reuters Point Carbon, referring to the Langeled pipeline, Britain's main gas import route from Norway.
A gas trader said supply was normal for the time of year.
Week-ahead prices also fell, sliding 1.40 pence to 69 pence, on forecasts for mild weather to continue for much of the week.
Further along the curve, gas for delivery in January 2014 was down 0.65 pence at 70.95 pence per therm. Gas for delivery in the first quarter of next year also eased, falling 0.70 pence to 70.60 pence per therm.
Mild weather also weighed down British baseload power prices for delivery on Tuesday which fell more than 2 pounds to 52.20 pounds per megawatt hour.
Prices were also capped by the return to service of the 550-MW Dungeness B-21 nuclear reactor on Saturday, improving the supply outlook for the coming week.
(Reporting by Nina Chestney and Joshua Franklin; editing by Keiron Henderson)