U.S. markets faltered early Monday, with debt concerns in Europe outweighing a 0.5 percent rise in personal income.
Germany warned during the weekend that Greece needed to act on the fiscal discipline measures it has endorsed. Leaders in Europe were meeting to discuss tighter fiscal controls and the fate of a bailout program for Greece.
In Washington, the Commerce Department said incomes rose in December, but consumer spending was flat, falling less than 0.1 percent from November.
In midmorning trading, the Dow Jones industrial average lost 127.87 points, 1.01 percent, to 12,532.59. The Standard & Poor's 500 index dropped 15.50 points, 1.18 percent, to 1,300.83. The tech-dominated Nasdaq composite index shed 32.14 points, 1.14 percent, to 2,784.41.
The benchmark 10-year treasury note rose 17/32 to yield 1.84 percent.
The euro fell to $1.3099 from Friday's $1.3219. Against the yen, the dollar fell to 76.39 yen from Friday's 76.71 yen.
In Tokyo, the Nikkei 225 index lost 0.54 percent, 48.17, to 8,793.05.