NEW YORK (CNNMoney.com) - Stocks looked to have a rough start to the holiday-shortened week Tuesday on a lower dollar and concerns about what Federal Reserve minutes might suggest about its future rate hike plans.

U.S. stock futures were down sharply in early trading, indicating a lower open for U.S. markets. The dollar was lower against the yen and the euro on news that U.S. Treasury Secretary John Snow will announce his resignation this morning and Goldman Sachs Chairman and CEO Henry Paulson will be named to succeed him.

The Fed is due to release minutes of its May 10 meeting Wednesday afternoon, and the anticipation of those minutes is already causing nervousness among investors returning to work Tuesday. Rising hopes last week that the Fed might pause its course of rate hikes at its June 29 meeting helped give stocks their first positive week after two weeks of decline.

Ahead of those minutes will be The Conference Board's reading on consumer confidence, due to be reported at 10 a.m. ET, is forecast to be down to 100 from the 109.2 reported for April.

Treasury prices were little changed, leaving the yield on the benchmark 10-year note at the 5.07 percent level reached late Friday ahead of the holiday.

Major markets in Asia closed lower Tuesday, while major European markets were down in early trading. British telecom Vodafone reported a record $40.9 billion loss, although shares of Vodafone gained about 2 percent in early trading as the company raised its dividend and the amount it planned to return to shareholders by $5.6 billion despite the loss.

Oil prices were slightly higher in early.

The June light crude futures contract for NYMEX was up 12 cents to $71.49 in electronic trading, while the July contract for Brent crude gained 15 cents to $70.74.

In corporate news, shares of General Motors were downgraded to a "sell" recommendation from a neutral rating by Deutsche Bank. The embattled auto manufacturer, by far the best performer on the Dow Jones industrial average, had posted further gains last week on upgrades by Merrill Lynch and Prudential. Its shares fell 2.5 percent in Frankfurt trading early Tuesday.

Shares of Wal-Mart Stores (Research) also were lower in Frankfurt trading after the world's No. 1 retailer said higher gas prices left its May sales gain at the low end of its earlier guidance. Wal-Mart and other major retailers are due to report May sales before the market open Thursday.

Senior management of gas and oil pipeline operator Kinder Morgan (Research) late Monday announced plans to take the company private for $100 a share, a premium of about 18.5 percent over its current valuation. The deal would be worth $13.4 billion.

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