UK GAS-Prompt prices rise on higher demand

* Demand is 39 mcm above seasonal norm

* Temperatures forecast to fall at weekend

LONDON, April 20 (Reuters) - British prompt gas prices rose on Wednesday morning due to higher demand for gas used in heating systems.

Gas for immediate delivery was up 0.30 pence at 28.65 p/therm at 0754 GMT from the previous settlement, while the weekend contract gained 0.15 pence to 28.50 p/therm.

Demand was forecast to be 242 million cubic metres (mcm) on Wednesday, 39 mcm above the seasonal norm.

Temperatures are expected to fall to below average at the weekend and remain colder than normal next week.

"The weather is turning colder for a while so heating demand has likely gone up," a UK-based gas trader said.

On the supply side, flows were expected to be 253.8 mcm/day, National Grid (LSE: NG.L - news) data showed, meaning the system was 11.8 mcm oversupplied.

Flows from Norway through Langeled and the UK Continental Shelf were higher than the previous day. Liquefied natural (Dusseldorf: LI5.DU - news) gas supply was also healthy, with three tankers already docked or due to arrive in Britain over the next week.

Gas contracts further along the curve followed a drop in oil prices. Gas for May delivery was down 0.30 pence at 27.40 p/therm, while the winter '16 contract fell 0.20 pence to 33.10 p/therm.

Crude futures fell on Wednesday after Kuwaiti oil workers ended a three-day strike that had cut the nation's crude output by around half, with worries about an oversupplied market returning to the fore.

In the Dutch gas market, the day-ahead price at the TTF hub was down 0.18 euro at 11.75 euros per megawatt-hour. In the European carbon market, front-year EU allowances were down 0.07 euro at 5.50 euros a tonne. (Reporting by Nina Chestney; Editing by Dale Hudson)