The Dow Jones industrial average edged down 45 points, or 0.3 per cent, to 17,992 as of 9:32 a.m. Eastern time Tuesday.
The Standard & Poor's 500 index eased five points, or 0.3 per cent, to 2,085. The Nasdaq slipped 12 points, or 0.3 per cent, to 4,794.
European markets fell and Greece's main index was down slightly.
Benchmark U.S. crude oil was flat at $53.60 a barrel in New York. Oil has fallen 50 per cent since June.
Bond prices rose. The yield on the 10-year Treasury note fell to 2.17.