UK GAS-Prices edge up in tight system despite low demand

* Gas system seen 2 mcm/d short

* Gas demand to be 15 pct below seasonal norm

* Colder weather expected for late April

LONDON, April 24 (Reuters) - British spot gas prices edged up on Thursday morning as lower imports from Norway left the system slightly undersupplied, despite low demand.

Gas prices for delivery within the day were trading at 49 pence a therm at 0815 GMT, up 0.30 pence since the opening. Prices for delivery on Friday were up 0.1 pence to 48.90 pence a therm.

Traders said the price increase was a result of a slightly short system.

"Supplies are tight today despite lower demand as import levels from Norway have dropped due to maintenance, and the preparation for supplies from a new well have reduced flows through the Langeled pipeline to 17 million cubic metres (mcm), half of what came through it yesterday," one gas trader said.

"Expectations of colder weather were also supporting prices," he added.

Britain's gas demand was expected to be 186 mcm on Thursday, over 15 percent below the seasonal norm, according to data from National Grid (LSE: NG.L - news) , but the data also showed that supply was 2 mcm short of demand.

Meteorologists said that average British temperatures were expected to drop from around 11 degrees Celsius on Thursday towards the seasonal norm of 9-10 degrees over the weekend and as low as 6 degrees by the end of the month.

GAS UK natural gas prices National Grid instant flows National Grid gas demand North Sea gas and power maintenance

POWER UK: baseload prices , peakload prices , outages FRANCE: baseload prices , peakload prices , outages, report GERMANY: baseload prices , peakload prices , outages, report CENTRAL EUROPE: report SWITZERLAND: outages, reservoir levels NORDIC (SES: MR7.SI - news) : report EU CARBON PRICES SPEEDGUIDE: (Reporting by Henning Gloystein; editing by Jane Baird)