LONDON, Nov 23: European stock markets mixed on Thursday when US and Japanese markets were closed, and dealers noted a broker downgrading of British water group Kelda.

London's FTSE 100 index of leading shares slipped by 0.25 per cent to 6,144.80 points, Frankfurt's DAX 30 index had edged up by 0.10 per cent to 6,482.40 and in Paris the CAC 40 was off by 0.16 per cent at 5,444 points.

The DJ Euro Stoxx 50 index of eurozone blue-chip shares had shed 0.11 per cent in value to 4,090.36 points.

The euro stood at 1.2972 dollars.

Wall Street shares had posted modest gains on Wednesday as bullish sentiment underpinned trading in a quiet session ahead of the Thanksgiving Day holiday.

German trading was boosted by a survey which showed that business confidence in the eurozone's biggest economy was back at its highest level for 15 years in November, suggesting that the current upswing is set to continue next year.

The widely watched Ifo business climate index rose to 106.8 points in November from 105.3 points in October, the research institute said in a statement.

At its current level, the index has returned to its level of June 2006, which itself was the highest level in 15 years.

In London however, shares in Kelda Group fell by 2.29 per cent to 916 pence after Citigroup downgraded the stock to 'sell' from 'hold' amid consolidation of the British water distribution sector.

The broker explained that the price of Kelda stock had already fully taken account of the possibility of a takeover.

In Frankfurt, shares in the energy company RWE gained 0.88 per cent to 83.55 euros following the announcement of an agreement to cooperate with the US firm Excelerate Energy in the area of liquified natural gas (LNG).

In Paris, shares in EADS were off by 0.33 per cent at 23.89 euros.

The Paris prosecutor has launched a probe into insider trading, distribution of false information and receiving ill-gotten shares in the aerospace group, a source close to the matter said.

Air France-KLM shares plunged meanwhile by 6.67 per cent to 30.10 euros on news that the Franco-Dutch airline was discussing alliance prospects with Italian carrier Alitalia.

On Wednesday in New York, blue chip stocks rose in thin trading and despite news of a dip in US consumer sentiment and an announcement by billionaire Kirk Kerkorian that he had cut his stake in General Motors. The Dow Jones Industrial Average closed up 0.04 per cent at 12,326.95 after drifting for most of the session.—AFP