U.S. stock index futures fell on Tuesday as worries mounted over Greek debt after Germany demanded new austerity measures and investors awaited another round of earnings and economic data.

Concerns over an aid package to Greece pushed the cost of insuring against a debt default to a record high and weighed on equities around the world.

Dow component DuPont

posted a first-quarter profit that beat expectations early Tuesday and raised its full-year profit view, sending its shares up 1.5 percent to $41.55 in premarket trading on light volume.

Ford Motor Co posted a profit that topped estimates and raised its 2010 outlook to solid profits. The stock was down 1.1 percent to $14.30 pretrade.

Technology shares will be in focus a day after Texas Instruments Inc reported earnings that beat estimates by a penny and gave a better-than-expected revenue outlook.

3M Co , U.S. Steel Corp and Broadcom Corp are all set report on Tuesday.

On the economic front, the S&P Case/Shiller Home Price Index for February will be released at 9 a.m. EDT,while the Conference Board reports April consumer confidence at 10 a.m. EDT.

S&P 500 futures fell 4.3 points 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 dropped 28 points, while Nasdaq 100 futures lost 8.5 points.

Energy companies will be in the spotlight as June crude futures fell 1.2 percent to $83.23 per barrel on fears the Greece problems could pressure demand.

Japan's Nikkei stock average <.N225> closed up 0.4 percent on Tuesday after it found solid support at its 25-day moving average at around 11,100, while European shares fell on Greece, led by banking stocks.

U.S. stocks edged lower Monday as bank shares declined on fears that financial reform legislation wending through Congress will curb profits, while strong Caterpillar results buoyed the Dow.

(Editing by Jeffrey Benkoe)