UK GAS-Spot price dips; forward contracts rise on firmer oil

* Oversupply dents spot price

* Domestic production rises as demand dips

May 20 (Reuters) - British spot gas prices fell on Friday in response to an oversupplied transmission system and lower demand.

Contracts further forward rose on the back of rising Brent crude oil prices after disruptions to supply from Nigeria and Venezuela.

Gas for immediate delivery fell 0.15 pence to 29.50 p/therm by 0833 GMT, while gas for Monday delivery followed crude oil prices higher, gaining 0.6 pence to 30.10 p/therm.

With (Other OTC: WWTH - news) demand expected to be 210 million cubic metres (mcm) per day and supply at 215.6 mcm, the system was 5.6 mcm/day oversupplied, National Grid (LSE: NG.L - news) data showed.

Imports through Norway's Langeled pipeline steaded at 31 mcm/day, while output from the UK Continental Shelf improved slightly as the Bacton Seal terminal ramped up after an outage.

Flows from Belgium stood at 34 mcm/day, unchanged from Thursday's levels.

Send-out from liquefied natural gas (LNG) terminals inched lower to 45 mcm/day thanks largely to the Dragon terminal halving flows to 5 mcm/day.

"Despite the oversupplied system, intra-day and healthy supply outlooks for the coming weeks, prompt contract have opened the session higher in line with support from the curve," said Andrew Crabtree, pricing and risk analyst at Wingas UK.

Gas for next-month delivery rose by 0.32 pence to 29.27 p/therm, while August gas climbed 0.4 pence to 29.92 p/therm.

Seasonal contracts also rose in line with oil prices, with winter 2016 up 0.25 pence at 35.85 p/therm, while summer 2017 gained 0.35 pence to 33.15 p/therm.

Oil prices rose on Friday as turmoil in Nigeria, shale bankruptcies in the United States and a crisis in Venezuela all contributed to tightening supplies.

In the Netherlands, the day-ahead gas price at the TTF hub rose by 0.12 euros to 13.02 euro per megawatt-hour.

In the European carbon market, front-year allowances eased by 0.03 euros, or 0.5 percent, to 5.97 euros a tonne. (Reporting by Oleg Vukmanovic in Milan; Editing by David Goodman)