Stocks fell on Tuesday as a drop in July consumer confidence and disappointing quarterly results and outlooks from Office Depot Inc and U.S. Steel Corp reignited concerns about the strength of recovery.

U.S. consumer confidence fell in July, according to the Conference Board, more than expected and marking the second consecutive monthly decline as a difficult labor market spurred caution among consumers.

My sense is that it's a relatively modest decline, and that the focus this week continues to be on corporate earnings and the improving real estate data, said Eric Kuby, chief investment officer at NorthStar Investment Management Corp in Chicago. The Case-Shiller data this morning is another sign that the real estate market is getting better, though slowly.

U.S. single-family home prices rose in May from April, the first monthly increase in nearly three years, suggesting prices may be stabilizing, according to Standard & Poor's/Case Shiller home price indexes released on Tuesday.

The Dow Jones industrial average <.DJI> dropped 34.99 points, or 0.38 percent, to 9,073.52. The Standard & Poor's 500 Index <.SPX> fell 6.53 points, or 0.66 percent, to 975.65. The Nasdaq Composite Index <.IXIC> shed 7.24 points, or 0.37 percent, to 1,960.65.

With the broader U.S. stock market now having rallied more than 40 percent from the 12-year lows of early March, investors want more evidence that the recovery is gaining traction to justify pushing stocks higher.

Office Depot , the No. 2 U.S. office supply retailer, reported a bigger-than-expected quarterly loss as the recession hurt demand from corporate customers. The stock slid 15 percent to $4.55.

U.S. Steel Corp reported a second-consecutive quarterly loss and said it expects all its business sectors to operate in the red in the third quarter.

The company said customer orders had increased, but the outlook for overall demand and economic recovery was uncertain. Its shares dropped 2 percent to $40.45.

Falling oil prices weighed on energy shares, with Exxon Mobil Corp down 1.1 percent to $71.88.

U.S. front-month crude declined 2.2 percent, or $1.53, to $66.84 a barrel.

(Additional reporting by Ryan Vlastelica; Editing by Padraic Cassidy)