* FTSEurofirst 300, Euro STOXX 50 both down 0.3 pct * Carlsberg sheds 6.8 pct after results miss, outlook disappoints * Italian vote a reason for caution on euro zone shares - SocGen * Natixis up 26.5 pct on restructuring plan By Francesco Canepa LONDON, Feb 18 (Reuters) - European shares extended losses to a third session on Monday after disappointing corporate earnings and nerves ahead of Italy's election, with technical charts pointing to further losses. Carslberg, the world's fourth-biggest brewer, sounded an alarm bell with a disappointing outlook and results, sending its shares down 6.8 percent in volume two and a half times the stock's 90-day average. It was the top faller on the FTSEurofirst 300 index, which was down 0.3 percent at 1,157.89 points by 1145 GMT. It fell for a third straight day as lacklustre corporate results led investors to take profits on the index, which rallied at the start of the year. The blue-chip euro zone Euro STOXX 50 was also down 0.3 percent, at 2,606 points. Trading volume was less than a third of its full-day average as Wall Street would be closed for Presidents' Day. French bank Natixis was a standout performer, however, rallying 26.5 percent in volume seven times its full-day average for the past 90 days as it unveiled plans to simplify its control chain, paving the way for higher dividends. Strategists said Italy's general elections were a further reason for overall caution in the market as the prospect of a fragmented parliament after the Feb. 24-25 vote fuelled concerns a new government could struggle to stay the course on reforms. Daniel Fermon, head of thematic strategy at Societe Generale, said the Euro STOXX 50 could fall as much as 10 percent if zone risk flares up again, hitting the single currency and leading investors who adopt quantitative strategies, or "quants", to sell shares. "I think many quants will continue to play this game because, statistically speaking, it has always worked this way for the last three years so they'll stick with this model," Fermon said. He recommended the pan-European blue-chip STOXX Europe 50 as a safer play thanks to its exposure to the defensive healthcare sector and its lower correlation to the euro. Investors would be looking for any hint about the European Central Bank's views on the common currency when President Mario Draghi testifies to the European Parliament on Monday afternoon. BLEAK CHARTS Charts on the euro zone Euro STOXX 50 also painted a bleak picture as the index edged below technical support at around 2,610, its 2012 high. The index's failure to break above the 55-day moving average last week was seen as a sign of further falls to come, with a technical support level at 2,505, the 50 percent retracement of the 2011 selloff, seen as a possible target. "I think we'll soon see a drop down to the 2,505 area," Anders Soderberg, chief technical analyst at SEB Bank in Stockholm, said. "If it's a correction, it ends there but there's certainly a growing risk for a more profound setback, confirmed ... below 2,500." The index has fallen 6 percent since late January as disappointing corporate results and nerves ahead of debt-laden Italy's election triggered some profit taking, although it has gained around 10 percent since the start of last year. Around 38 percent of STOXX Europe 600 companies that have reported results so far have missed consensus forecasts, leading analysts to cut their 2013 estimates by 2.2 percent in the past 30 days, Starmine data showed. Strategists at JPMorgan said falling earnings estimates were capping the upside for equities, with cyclical shares, which depend on economic growth and tend to show a greater correlation to the earnings cycle, as the most likely underperformers.