The Dow Jones industrial average was down 128 points, or 0.8 per cent, to 15,367 shortly before noon Friday.
The Standard & Poor's 500 index was down nine points, or 0.6 per cent, at 1,688.
The Nasdaq composite was down 14, or 0.4 per cent, at 3,654.
The S&P 500 is heading for its first weekly loss in seven weeks. It closed at a record high a week ago.
The market has been mostly slipping this week as companies report mixed earnings and disappointing revenue.
Gap fell 4 per cent to $43.63 after reporting that its sales edged up just 1 per cent last month, less than analysts were expecting.