UPDATE 1-French broadcaster M6 2008 sales down 0.1 pct

*M6 total 2008 sales 1.355 billion euros, above average estimate

*2008 advertising revenue at M6 channel down 2.6 percent

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PARIS, Jan 20 (Reuters) - M6 (MMTP.PA), France's second-largest commercial TV broadcaster, said on Tuesday 2008 sales eased 0.1 percent as a deteriorating economic climate hit advertising revenue at its flagship channel.

M6, known for news-related programmes such as "Forbidden Zones", said sales reached 1.355 billion euros ($1.76 billion) from 1.356 billion euros in 2007, slightly above the average estimate of 1.352 billion euros from 16 analysts polled by Reuters Estimates.

Advertising revenues fell 2.6 percent to 658 million euros at its flagship M6 channel in the full year and fell 6.6 percent in the fourth quarter alone.

M6, formed in 1987 and listed in 1994, has a market capitalisation of 1.61 billion euros.

Like larger domestic rival TF1 (TFFP.PA), it faces competition from new media such as the Internet and a gloomy advertising market. ($1=.7705 Euro) (Reporting by Dominique Vidalon; Editing by Hans Peters)