UK GAS-Prompt slips on oversupply, stronger oil buoys curve

* Gas market 13.9 mcm oversupplied

* Outage ends at Bacton Seal terminal

LONDON, March 11 (Reuters) - British gas for immediate delivery fell on Friday due to an oversupplied system while curve prices were buoyed by higher oil.

Gas for immediate delivery fell 1.45 pence or 4.7 percent to 29.15 pence per therm at 0915 GMT.

Britain's gas system was oversupplied by 13.9 million cubic metres (mcm), with demand forecast at 290.7 mcm and supply at 304.6 mcm, National Grid (LSE: NG.L - news) data showed.

Imports from Norway through the Langeled pipeline were near full capacity around 70 mcm on Friday.

Domestic supplies were also lifted by the return to service of Britain's Bacton Sea gas terminal where gas flows had been cut since March 4 due to an unplanned outage.

Traders said mild weather had curbed demand, contributing to the oversupply in the system.

Britain's Met Office said temperatures would reach as high as 10 degrees Celsius in the south of the country on Friday.

Gas for day-ahead delivery, however, inched up by 0.10 pence to 29.60 p/therm and prices for the weekend were 0.25 p higher at 29.50 p/therm.

Benchmark Brent crude oil futures rose 1.5 percent on Friday to more than $40 a barrel, helping to lift longer-term gas prices.

The April contract was up 0.12 pence to 28.05 pence per therm while the Winter 2016 gas contract rose 0.15 pence to 33.25 pence per therm.

In the Netherlands, the day-ahead gas price at the TTF hub was 0.1 euros higher at 12.23 euros per megawatt-hour (MWh).

In Europe's carbon market the front-year EU Allowance (EUA) price rose 0.08 euros to 5.00 euros per tonne. (Reporting by Susanna Twidale)