* Futures: Dow down 15 pts, S&P unchanged, Nasdaq up 7 pts
By Tanya Agrawal
July 21 (Reuters) - U.S. stock index futures were little changed on Tuesday ahead of a raft of earnings from technology giants, including Apple, and as the dollar continued to trade at a three-month high.
* The dollar index was down marginally at $97.88, its highest level since April on firming expectation of a U.S. interest rate hike later in the year.
* A fall in commodities capped gains on Monday with gold and other precious metals trading near five-year lows.
* Oil prices continued their downward spiral with U.S. crude oil falling below $50 earlier on Tuesday.
* Tech giants such as Yahoo, Microsoft and Apple are scheduled to report results after the closing. Strong earnings from technology companies have been driving gains in the Nasdaq.
* On Friday, the Nasdaq composite touched a new intra-day high for the third straight day while the S&P 500 was just shy of its all-time high.
* While markets are at record highs, June-quarter earnings of S&P 500 companies are expected to dip 2.1 percent, with revenue dropping 2.1 percent, according to Thomson Reuters data.
* Of the companies that have reported earnings so far, 70 percent have reported earnings above analyst expectations, above the 63 percent average beat rate since 1994.
* However, 55 percent have topped revenue forecasts, below the 61 percent average beat rate since 2002. U.S. companies were expected to post their worst sales decline in nearly six years in the second quarter, in part due to the strong dollar that reduces the value of U.S. companies' overseas income.
* International Business Machines Corp's shares fell 5 percent to $164.46 in premarket trading, a day after the company's revenue fell for the 13th consecutive quarter.
* Qualcomm was up 3.1 percent to $65.78 after a tech website said the chipmaker is preparing to lay off several thousand employees, or more than 10 percent of its 30,000-strong workforce.
* United Technologies fell 2.2 percent to $108.01 after the company cut its full-year profit outlook as it warned of pressures in its aerospace systems and Otis elevators businesses.
Futures snapshot at 7:17 a.m. ET (1117 GMT):
* S&P 500 e-minis remained unchanged, with 52,605 contracts traded.
* Nasdaq 100 e-minis were up 6.75 points, or 0.14 percent, on volume of 10,143 contracts.
* Dow e-minis were down 15 points, or 0.08 percent, with 7,261 contracts changing hands. (Editing by Don Sebastian)