* Market undersupplied by 42 mcm
* Unplanned outage at Norway's Kollsnes
LONDON, April 14 (Reuters) - British spot gas prices rose on Thursday morning as outages in Norway cut gas exports to Britain, leaving the system undersupplied.
Gas for within-day delivery fetched 29.00 pence per therm at 0811 GMT, up 0.60 pence from the last settlement.
Gas for day-ahead delivery rose 0.40 pence to 28.25 pence per therm.
Norwegian imports to Britain through the Langeled pipeline were around 20-40 mcm on Thursday morning, up from levels over 60 mcm the previous day, National Grid data showed
An unplanned outage at Norway's Kollsnes gas processing plant cut supply by 57.2 mcm/day while an outage at the country's Visund gas field reduced supply by 7 mcm/day.
British gas prices further along the curve were dragged lower by weak oil prices, traders said.
The Winter '16 contract fell by 0.10 pence to 32.60 pence per therm. The Summer '17 contract fell by 0.20 to 29.60 pence per therm.
Brent crude oil prices dropped below $44 a barrel on Thursday as OPEC warned of slowing demand and Russia hinted that there might only be a loose agreement at the upcoming oil exporter meeting to rein oversupply.
In the Netherlands' gas market, the day-ahead price at the TTF hub slipped 0.05 euros to 11.30 euros per megawatt-hour.
In Europe's carbon market, the front-year EU Allowance price fell 0.06 euros to 5.47 euros per tonne. (Reporting by Susanna Twidale)