U.S. stocks fell, halting a three- day rally, as United Parcel Service Inc. slumped, economic reports missed estimates and uncertainty grew over how much progress European leaders are making in debt-crisis talks.

UPS, whose deliveries make it a proxy for the economy, lost 2.1 percent as international shipping growth began to cool while U.S. expansion stagnated. 3M Co., the maker Scotch-Brite sponges, sank 6.3 percent after cutting its profit forecast. Netflix Inc. plunged 35 percent as the company projected losses in 2012. Amazon.com Inc. tumbled 14 percent after the close of regular trading as earnings missed analysts’ projections.

The Standard & Poor’s 500 Index fell 2 percent to 1,229.05 as of 4 p.m. New York time, after gaining 3.7 percent over the previous three days. All 10 S&P 500 groups declined as a gauge of financial shares slid 3.1 percent. The Dow Jones Industrial Average sank 207 points, or 1.7 percent, to 11,706.62. The Russell 2000 Index of small companies lost 3 percent.

“It’s going to be a slow recovery,” Mark Bronzo, who helps manage $23 billion at Security Global Investors in Irvington, New York, said in a telephone interview. “The economic data show that we’re in a bottoming process. UPS gave some cautious commentary concerning global growth. In addition, we’re still slave to the events in Europe.”

The S&P 500 rose from the threshold of a bear market early in October on steps by European leaders to support banks and higher-than-estimated corporate earnings. The benchmark gauge for American equities has rallied 8.6 percent so far in October, following a five-monthdecline.