The Standard & Poor's 500 index slipped 12 points, 0.7 per cent, to 2,006 in midday trading Tuesday. Energy company Denbury Resources fell the most among companies in the index.
The price of benchmark U.S. crude oil was down $1.86, or 4 per cent, to $47.27 a barrel.
The Dow Jones industrial average fell 139 points, or 0.8 per cent, to 17,372, pulled lower by a 3 per cent fall in Johnson & Johnson's stock. The health care giant's profit dropped 28 per cent in its latest quarter.
The Nasdaq fell 24 points, or 0.5 per cent, to 4,609.