Europe Power-French strike plan heightens spot spread

* France very tight, Germany well supplied for short term

* Cooler weather on its way from next weekend

* Curve prices trend lower

FRANKFURT, Oct 8 (Reuters) - European prompt power prices diverged on Monday as French levels rose on tight nuclear supply and as Germany's fell on a better capacity outlook.

The tightening of safety rules for nuclear plants has led to longer maintenance periods, which has reduced supply for several months.

Furthermore, an announcement by French union CGT of a planned 24-hour strike for Tuesday drove the French price premium even higher over its neighbouring market.

The French contract for Tuesday delivery firmed 2.25 euros to 56.25 euros ($73.46) a megawatt hour (MWh) from levels paid for Monday, while in Germany the corresponding day-ahead contract was down 5 euros to 45.50 euros in the over-the-counter market

.

"We should be drifting further apart price-wise," a German trader said about the two markets, which are partially linked via interconnectors. "Especially wind power will be in high supply here," he added.

CGT said the strike action, triggered by planned site closures, would hit thermal power and nuclear output, if to a lesser degree. Nuclear capacity last stood at just over 70 percent of total availability.

For the medium term, France's weather was expected to be relatively benign for this week, but weekend temperatures already looked cold. Consumers in the country rely heavily on electric heating devices.

This caused French week-ahead prices to jump 9 euros to 60 euros, from what had been paid for the week just started. Germany's week-ahead contract gained 1 euro to 49 euros.

Germany's weather is likely to range between 10 to 16 degrees Celsius this week, falling to a maximum of 10 degrees next week. German homes are heated with gas and oil, which means its power market does not respond as much to temperature changes as France's.

In thermal plant outages, RWE showed its newly commissioned Neurath G brown coal block of 1,050 MW was shut for its first maintenance last Friday and was due to reopen on Oct. 18.

RWE also presented updated schedules for maintenance outages at its thermal plants for 2012 and 2013.

Along the forwards power curve, Germany's benchmark contract for 2013 delivery

fell 20 cents to 47.80 euros/MWh, and the French contract for the same delivery period slipped by 10 cents to 50.75 cents.

Traders cited the weak German spot price and retreating oil prices.

Brent crude fell below $111 per barrel on concerns slower economic growth would curb oil demand, but supply worries on tension in the Middle East helped check losses.

Coal, carbon and gas prices were also lower.

($1 = 0.7657 euros)

(Reporting by Vera Eckert; editing by Jane Baird)

((vera.eckert@thomsonreuters.com)(+49 69 7565 1228)(Reuters Messaging: vera.eckert.thomsonreuters.com@reuters.net))

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Keywords: MARKETS EUROPE/ELECTRICITY