US stocks opened lower Monday after breaking a six-week slump with solid gains last week, with the jury still out over how strong the crucial Black Friday holiday sales went for retailers.

Five minutes into trade, the Dow Jones Industrial Average was down 74.27 points (0.57 percent) at 12,935.41.

The broad-market S&P 500 index lost 7.15 (0.51 percent) to 1,402.00, while the Nasdaq Composite fell 7.79 (0.26 percent) to 2,959.056.

Traders' eyes were also on whether European officials and the International Monetary Fund could come to agreement on a deal to keep Greece's bailout program going and avoid forcing Athens into default on its debt. - Sapa-AFP