A measure of global equities has fallen 10 percent from this year’s high in May, as concern grows that the economic recovery is faltering, Bloomberg reported.

The MSCI All-Country World Index of stocks in developed and emerging markets slid 1.2 percent to 320.91 today in London, extending the decline from its nearly three-year high on May 2 to 10.3 percent. The index is on course for its largest weekly drop since May, after retreating 4.5 percent over the past four days.

U.S. reports this week showed an unexpected drop in consumer spending, and slower-than-forecast growth in manufacturing. Ratings companies said they may downgrade the country’s debt even after President Barack Obama signed a measure to increase the government’s debt ceiling to prevent default.

“Three main sources of uncertainty have weighed on risky assets in recent weeks: the global growth slowdown, the fiscal crisis in the euro zone and the discussions about the U.S. debt ceiling,” Joost van Leenders, a strategist at BNP Paribas Investment Partners in Amsterdam, wrote in a report. “This last issue has been solved for now, but the other two came back with a vengeance.”

Other major stocks tumbled at the open today. The Dow Jones industrial average dropped 1.31 percent. The Standard & Poor’s 500 index was down 1.64 percent. The Nasdaq composite index dropped 1.8 percent.