European stocks, including the STOXX 600, opened sharply lower on Wednesday, as global markets were rattled by concerns of an imminent slowdown in the United States. Futures tied to Wall Street's main indexes slipped ahead of labor data expected later on Wednesday, reflecting worries about the health of the U.S. economy. European stocks continued to edge lower on Thursday, marking the fourth straight session of declines, as investors awaited more economic data from the euro zone and tracked U.S. jobs data to gauge the Federal Reserve's outlook. Sentiment was also weighed down by slowing growth in China. U.S. stock index futures remained flat to marginally lower ahead of a series of economic data on Thursday, as investors sought clues about the size of the Federal Reserve's anticipated interest rate cut.