NEW YORK (CNN/Money) - U.S. stocks opened sharply lower Monday after IBM said first-quarter profit likely missed Wall Street forecasts by a wide mark, unnerving investors already worried about rising oil prices in the wake of an Iraqi export shutdown.

At 9:40 a.m. ET, the Dow Jones industrial average, home to IBM, lost 136.80 points to 10,134.84, while the tech-laden Nasdaq composite index fell 27.52 points to 1,742.51. The Standard & Poor's 500 index declined 9.95 to 1,112.78

Blaming a "tough" business environment, IBM (IBM: down $9.27 to $87.98, Research, Estimates), the No 1 technology company in terms of sales, said profit in its first quarter will range from 66 cents a share to 70 cents a share when the company reports full details April 17. Analysts surveyed by First Call were looking for 85 cents a share.

The price of Brent crude rose as high as $26.80 a barrel in London after Iraq suspended all oil exports for 30 days or until Israeli forces withdraw from Palestinian territory.

Overseas, Europe's stocks slipped while Asia's were mixed. The dollar rose against the euro and slipped versus the yen. Treasury securities rose.