Wall Street was poised for a lower open on Tuesday as housing data failed to counter pessimism about the economy.

Prices of U.S. single-family homes gained more than expected in June and rose in the second quarter, reflecting the lingering boost from homebuyer tax credits that ended in April, Standard & Poor's/Case Shiller home price indexes showed.

Investors were unmoved by the data in light of recent economic reports showing a slowdown in the economic recovery.

The problem with the market is the time of the year, with a lot of investors on vacation and also increasing evidence that the pace of the economic recovery is slowing and concern that trend could get worse, said Tim Ghriskey, chief investment officer of Solaris Asset Management in Bedford Hills, New York. That certainly scares people.

At 10 a.m. EDT. (1400 GMT), the Conference Board's consumer confidence index will be released, with economists forecasting an increase to 50.5 in August from 50.4 in July, which was the lowest reading since February.

Later Tuesday, the Federal Reserve releases minutes from its August 10 policy meeting, where it endorsed a more dovish monetary posture, citing a willingness to reinvest in monetary accommodation. Last week Fed Chairman Ben Bernanke said in a speech the recovery had weakened more than expected.

S&P 500 futures were down 0.7 point and were below fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures slipped 7 points, and Nasdaq 100 futures lost 9.25 points.

Monsanto Co dropped 3.8 percent to $53.80 in premarket trading after the seeds maker gave a full-year 2010 earnings outlook below expectations.

(Reporting by Chuck Mikolajczak; editing by Jeffrey Benkoe)