UK GAS-Within-day prices rise as Norwegian imports dip

* Imports through Langeled drop

* Market 5.5 mcm undersupplied

LONDON, April 7 (Reuters) - British spot gas prices for immediate delivery rose on Thursday morning as lower imports from Norway led to an undersupplied system.

Within-day gas was at 28.00 pence per therm at 0800 GMT, up 0.55 pence since the last settlement.

With (Other OTC: WWTH - news) supply flows at about 265.9 million cubic metres (mcm) per day on Thursday and demand expected to be about 271.4 mcm, the system was 5.5 mcm undersupplied, National Grid (LSE: NG.L - news) data showed.

Imports from Norway via the Langeled pipeline, Britain's main sub-sea gas import route, were under 50 mcm on Thursday morning, National Grid data showed, down from levels near 60 mcm over the previous day.

British gas prices for day-ahead delivery were little changed at pence at 27.85 pence per therm, down 0.03 pence.

Further along the curve prices for May and June delivery slipped 0.15 pence per therm and 0.22 pence per therm respectively to 26.80 pence per therm and 25.83 pence per therm.

Gas analysts at Thomson Reuters (Dusseldorf: TOC.DU - news) said British gas consumption and exports to Ireland (Other OTC: IRLD - news) are likely to rise this summer to 27.5 billion cubic meters (bcm), up 0.9 bcm from the previous year.

The rise will come due to an increase in demand for gas from the power sector on the back of closure of several coal-fired power plants in Britain and as the domestic carbon tax continues to improve the profitability of gas plants over coal, the analysts said in a seasonal outlook published late on Wednesday.

However, the analysts said a surge in exports of liquefied natural gas (LNG) to Europe will continue to weigh on prices despite the uptick in demand.

In the European carbon market, front-year EU allowances edged down 0.01 euros to 5.30 euros a tonne. (Reporting by Susanna Twidale)