The Dow was off 118 points at 13,891 shortly before noon Eastern time. Travelers and Merck fell the most of the 30 stocks in the index.
The Standard & Poor's 500 index dropped 13 points to 1,499. The Nasdaq composite index fell 37 to 3,142.
On Friday the Dow closed above 14,000 for the first time since 2007, before the financial meltdown that routed world markets.
The Dow is still up 6 percent this year. Yet Wall Street's celebratory mood was a distant memory Monday, as U.S. stocks followed European markets lower. France's CAC-40 was down 2.9 percent, Germany's DAX 2.4 percent.