Europe shares sag as Ukraine woes, mixed updates weigh
* FTSEurofirst 300 down 0.6 pct, Euro STOXX 50 down 0.7 pct
* SABMiller, Nestle give weak updates
* Germany's DAX sinks as tension mounts in Ukraine
By Blaise Robinson and Sudip Kar-Gupta
PARIS/LONDON, April 15 (Reuters) - Worries over escalating tension in Ukraine and weak updates by bellwethers including Nestle held back European stocks on Tuesday.
At 1428 GMT, the FTSEurofirst 300 index of top European shares was down 0.6 percent, at 1,311.35, resuming last week's slide during which the index lost about 3 percent, before slightly bouncing back on Monday.
The euro zone's blue-chip Euro STOXX 50 index was down 0.7 percent at 3,108.98 points, testing a key support level, its 50-day moving average, for the third straight session. Breaking below it would send a bearish technical signal.
"We're cautious in the short term, we're waiting to see how the geopolitical situation evolves. There are a lot of uncertainties about Ukraine, which could become a negative catalyst for stocks if things spin out of control," Barclays France director Franklin Pichard said.
Russia declared Ukraine on the brink of civil war on Tuesday as Kiev said an "anti-terrorist operation" against pro-Moscow separatists was under way, with troops and armoured personnel carriers seen near a flashpoint eastern town. Continuación...