UK GAS-Prompt prices fall as imports from Norway and temperatures rise

* UK gas market almost balanced

* Flows through Langeled rise over 40 mcm

LONDON, June 3 (Reuters) - British prompt gas prices fell on Friday morning, as imports from Norway rose, while expectations of warmer weather curbed demand.

Gas for within-day delivery fetched 34.50 pence per therm at 0850 GMT, down 0.45 pence from their last settlement.

Gas for day-ahead delivery fell 0.60 pence to 34.70 pence per therm.

"Prompt prices have opened the session marginally lower, in line with stronger levels of imported supply and the potential for warmer conditions over next week," said Marcel Boonaert, head of gas trading at Wingas UK.

Norwegian imports through Langeled, Britain's main gas import pipeline, were over 40 million cubic metres (mcm), up from levels below 30 mcm the previous day, National Grid (LSE: NG.L - news) data showed.

With (Other OTC: WWTH - news) supply flows at 178.4 mcm and demand expected to be 179.4 mcm/day, Britain's gas system was almost balanced, the data showed.

Demand for gas is expected to dip in the coming days as temperatures rise.

Britain's Met Office forecast temperatures would top 20 degrees Celsius in the south on Saturday, having been below that level for most of the week.

Gas prices further along the curve slipped.

The Winter '16 gas contract was down 0.23 pence at 38.30 pence per therm.

In the Netherlands' gas market, the day-ahead price at the TTF hub was down 0.16 euro at 14.52 euros per megawatt-hour.

In Europe's carbon market, the front-year EU allowance price fell 0.04 euro to 5.99 euros per tonne.

(Reporting by Susanna Twidale; editing by Jason Neely)