European stock markets opened lower on Wednesday as increasing risks of a civil war in Ukraine hit investing sentiment. The Stoxx Europe 600 index dropped 0.3% to 334.95, setting it on track for a fourth straight day in the red. Among country-specific indexes, France's CAC 40 dropped 0.5% to 4,406.53, Germany's DAX 30 fell 0.4% to 9,431.78 and the U.K.'s FTSE 100 gave up 0.3% to 6,776.09. Posting some of the biggest losses in Europe, shares of CGG lost 6.6% after the geoscience company reported first-quarter earnings. Carlsberg AS erased 1.2% after the Danish brewer cut its full-year guidance due to the situation in Russia, which is its single largest market.