UK GAS-Prices fall as Rough prepares to reopen for withdrawals

* Centrica (Frankfurt: A0DK6K - news) to restart Rough withdrawals from Dec. 9

* Gas system oversupplied by 7 mcm/day despite high demand

Nov 30 (Reuters) - British wholesale gas prices fell on Wednesday morning after Centrica said it would restart gas withdrawals from Britain's largest storage site Rough next week.

Gas for immediate delivery fell by 0.75 pence to 48.80 pence per therm by 1027 GMT, while the day-ahead contract lost 1.1 pence at 48.70 pence/therm.

The site, which has been shut since June for well testing, will restart gas withdrawals no later than on Dec. 9, with at least 18 wells available, operator Centrica said.

Centrica imposed reductions on how much gas could be stored at Rough last year as a safety precaution after identifying potential issues with well integrity. This June, it stopped both withdrawal and injection of gas.

Britain depends in large part on stored reserves to manage winter demand spikes while domestic stockpiles also help ensure security of energy supplies.

"The (market's) reaction should be an initial sell-off as we see now, especially the cold months all the way to the end of the first-quarter," a trader said.

Gas prices for January fell by 1.4 pence to 48 pence per therm, while prices for December were down by 0.55 pence at 48.25 pence/therm.

"I see a small downside (to prices) but no major movement. We have been managing increased demand with ease over recent days including today," said Wayne Bryan, senior analyst at Alfa Energy.

Slightly milder temperatures and an increase in deliveries from Norway after outages at the Norwegian gas plants Kollsnes and Nyhamna ended were also weighing on prompt prices.

While temperatures in the south of Britain could fall overnight to 6 degrees Celsius, maximum day temperatures could rise by one or two degrees from that, Britain's Met Office said.

Wednesday's gas demand, at 352 mcm per day, was 25 percent above normal seasonal demand. Flows were forecast at 359 mcm/day, leaving the gas system slightly oversupplied.

In the Netherlands, the day-ahead gas price at the TTF hub fell by 0.17 euro to 18.23 euros per megawatt-hour (MWh).

In the European carbon market, the benchmark Dec. 16 contract eased by 0.09 euro to 4.47 euros a tonne.

EU regulators will unveil reforms on Wednesday to promote a greater share of renewables in Europe's grid by 2030, with plans to cut energy use by 30 percent, phase out subsidies for coal-fired plants and enforce greater cross-border trade.

In the UK power market, the baseload day-ahead price rose by 2.5 pounds to 56.50 pounds per MWh. (Reporting by Nerijus Adomaitis in Oslo; Editing by Nina Chestney)