Wall Street was set to open slightly higher on Tuesday as a wave of companies reported good earnings, but the dearth of blockbuster results threatened to cool off a recent rally.

Goldman Sachs Group Inc shares were up 1.6 percent to $165.90 in premarket trading after it said first-quarter earnings nearly doubled, easing concerns after the Wall Street powerhouse was charged with fraud last week.

Earnings overall are good, but you better beat these heightened expectations or else your stock is going to take a breather after the run we've had going into earnings, said Peter Boockvar, equity strategist at Miller Tabak & Co in New York.

He said the equities rebound started in Europe on positive news from companies, including Daimler AG , up nearly 8 percent after posting results.

Adding to the positive tone, a widely followed German monthly poll of economic sentiment topped forecasts, boosting expectations the economy will pick up.

S&P 500 futures rose 4.6 points and were slightly above 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 gained 25 points and Nasdaq 100 futures added 5.75 points.

The S&P 500 <.SPX> rose last week to a more than 18-month high, up 79 percent from the lows reached in March 2009.

UnitedHealth Group Inc jumped 4.6 percent to $32.65 premarket after the largest U.S. health insurer soared past estimates and raised its full-year earnings forecast.

Johnson & Johnson rose 0.6 percent at $66.45 after reporting better-than-expected earnings on strong sales growth of medical devices, but it trimmed its 2010 forecast.

Coca-Cola Co fell 1.6 to $54.45 after posting higher profits, but revenue fell short of estimates.

Commodity-linked stocks could show strength after the U.S. dollar index <.DXY> retreated slightly following three days of gains.

Crude oil futures topped $82 a barrel, rebounding from three-week lows, as jet fuel demand increased after European planes began flying again. A massive ash cloud originating in an Icelandic volcano receded, freeing European airspace after five days of airport closures.

International Business Machines Corp declined 2.1 percent to $129.50 in early trading a day after posting better-than-expected profits but disappointing gross margins.

Other major companies set to announce results include Apple Inc and Yahoo Inc .

U.S. stocks rose on Monday as investors reassessed the potential damage of the Goldman fraud case and earnings optimism grew.

(Editing by Jeffrey Benkoe)