US STOCKS-IBM, United Tech drag Dow; Apple earnings on deck
* IBM down after revenue falls for 13th straight quarter
* United Technologies cuts full-year profit outlook
* Microsoft, Yahoo fall after results; Apple on tap
* Indexes down: Dow 1.00 pct, S&P 0.43 pct, Nasdaq 0.21 pct (Updates to close, adds Microsoft and Yahoo shares)
By Chuck Mikolajczak
July 21 (Reuters) - U.S. stocks fell on Tuesday in the wake of results from IBM and United Technologies that dampened early optimism over earnings season ahead of quarterly profits from tech giants including Apple and Microsoft.
The Dow fell 1 percent, with IBM and United Tech contributing around 118 points to the 181-point drop. The decline marked the biggest percentage decline in about two weeks for the blue-chip index.
IBM's shares were down 5.9 percent to $163.07, a day after the company's revenue dropped for the 13th consecutive quarter and fell short of analyst expectations.
Fellow Dow component United Technologies tumbled 7 percent to $102.71 and was the worst performer on the Dow after cutting its full-year profit outlook for the third time this year. Continuación...