Updated with recent oil prices. NEW YORK ( TheStreet) -- Crude oil futures were down before the stock market open on Tuesday. Light, sweet crude for delivery in September was losing 57 cents to $68.39 in electronic trading on the New York Mercantile Exchange. Earlier, the price dipped below $68. On Monday, the contract gained 33 cents to settle at $68.38. It's a big week for many of the major oil concerns, as many begin reporting earnings this week. On Monday, most of the major oil stocks finished in positive territory. Exxon Mobil ( XOM), which reports its quarterly earnings on Thursday, closed up 0.6%, or 46 cents, to finish at $72.75. Chevron ( CVX), which reports on Friday, gained 0.6%, or 42 cents, to $68.85. Reporting Wednesday is ConocoPhillips ( symbol), which also tracked up 0.7%, or 30 cents, to $45.25. On Tuesday, BP ( BP) reported a 53% drop in profit in its second quarter . On Monday, BP ticked up 1.4%, or 69 cents, to $51.34. But following the earnings announcement, BP's American depositary receipts were backtracking before the opening bell. --Reported by Sung Moss in New York.