LONDON, Feb 1 (Reuters) - British gas prices moved higher on

Friday as the system was left short by lower flows from UK

gasfields, fewer imports and less liquified natural gas remains,

while colder weather will drive demand for heating, traders said

Friday.

The within-day gas price gained 1.50 pence day on day to

67.20 pence per therm, while day-ahead gas traded up 1.35 pence

at 66.90 pence.

'A mix of factors are impacting the prompt contract, lower

supply and colder weather while the lengthy reduction in supply

from Troll (Norway's largest gasfield) is supporting the March

contract,' said a trader at a utility.

The UK gas system was short at around 15.5 million cubic

metres per day (mcm/day), National Grid data showed, while

forecast demand of 294.7 mcm exceeeded predicted supply of 279.2

mcm, according to data from National Grid.

Demand is expected to be 3.2 percent below seasonal norms

the same data showed, although colder weather is expected after

a recent spell of milder temperatures, the Met Office forecast.

Analysts at Reuters Point Carbon said the fall in supply was

mainly the result of weaker flows through the Vesterled pipeline

into the St Fergus terminal, where supply was down to 25 mcm/day

from over 35 mcm/day on Thursday, from while supply to

continental Europe rose.

The IUK pipeline once again flipped into import mode, with

8 mcm/day expected to flow from Belgium to Britain, while supply

from the South Hook LNG terminal is expected to fall to around 5

mcm, down from 9 mcm on Thursday.

'With no new cargoes observed for the terminal, reduced LNG

supply is expected to continue also in February. Langeled and

BBL (pipelines) are also flowing lower today,' the analysts

said.

Further along the curve, traders said that lower output at

Norway's Troll gas field, which will last until early April,

would continue to support month-ahead prices.

March gas gained 0.35 pence to 65.60 pence.

Further-out gas prices were also supported by strong crude

oil, with the British front-season gas price rising to 63.35

pence, up from 62.80 on Thursday morning.

Brent crude was trading at $115.62 a barrel on Friday, and

earlier hit $115.91, its highest level in more than three

months, as escalating tension in the Middle East stoked supply

worries.

British over-the-counter (OTC) power prices rose day on day

on the back of fossil fuel plant outages, even though underlying

healthy supply margins kept prices comparatively low.

Day-ahead power traded at 48.63 pounds per megawatt-hour, up

around 0.68 pounds on the previous session.

(Reporting by John McGarrity, editing by William Hardy)

((john.mcgarrity@thomsonreuters.com)(+44 207 542 4779)(Reuters

Messaging:)(john.mcgarrity.reuters.com@reuters.net))

((Summer 2013

Day-ahead gas

WEATHER

DEMAND AND SUPPLY

TECHNICALS

POWER

GAS

UK natural gas prices

National Grid instant flows

National Grid gas demand

North Sea gas and power maintenance

POWER

UK: baseload prices, peakload prices,

outages

FRANCE: baseload prices, peakload prices, outages, report

GERMANY: baseload prices, peakload prices, outages, report

CENTRAL EUROPE: report

SWITZERLAND: outages, reservoir levels

NORDIC: report

EU CARBON PRICES SPEEDGUIDE:

Keywords: MARKETS BRITAIN GAS/POWER

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