By Rodrigo Campos
NEW YORK (Reuters) - U.S. stock index futures fell on Tuesday, weighed by company earnings results including those of sector bellwethers MICROSOFT (MSFT.NQ)and CATERPILLAR (CAT.NY)
* Concerns lingered over Greece's new anti-bailout government and its implications for the euro zone. The leftist government that came to power in Athens following elections on Sunday looks set on a collision course with the country's creditors. U.S.-traded shares of the National Bank of Greece
* Shares of Microsoft
* Shares of construction and mining equipment maker Caterpillar
* Market participants were watching out for a snowstorm that appeared to have spared New York City but continues to pound parts of the U.S. Northeast. New York Stock Exchange and Nasdaq spokesmen said Tuesday would be business as usual.
* Economic data expected on Tuesday includes December durable goods orders at 8:30 a.m. EST (1330 GMT), November Case Shiller home prices half an hour later and Markit's gauge of the U.S. services sector growth at 9:45 a.m. (1445 GMT). New home sales and consumer confidence data are also due shortly after the opening bell on Wall Street.
* Facebook shares fell 1.1 percent premarket after access to the world's largest social network and its Instagram photo-sharing site was blocked around the world for up to an hour on Tuesday. The company said the reason was an internal fault and not an outside attack.
* Procter & Gamble
* Pfizer
Futures snapshot at 7:56:
* S&P 500 e-minis
* Nasdaq 100 e-minis
* Dow e-minis <1YMc1> were down 195 points, or 1.11 percent, with 21,695 contracts changing hands.
(Reporting by Rodrigo Campos; Editing by Chizu Nomiyama)