NEW YORK, Oct 21 (Reuters) - U.S. stock index futures were higher on Tuesday, pointing to a fourth straight session of gains, with technology shares especially poised for outperformance following strong results from both Apple Inc and Texas Instruments Inc.
* The S&P 500 has gained 2.2 percent over the past three sessions, rebounding after a four-week decline that took the benchmark index down nearly 10 percent from its intraday record.
* Despite the strength over the past week, Wall Street has yet to recover from its recent pullback, which was driven by concerns over global growth. The S&P closed below its 200-day moving average for the sixth straight session on Monday and appeared to find resistance at that level. The CBOE Volatility index, a measure of investor anxiety, jumped 51 percent over the previous two weeks, although it fell 15.5 percent on Monday and closed below its 14-day moving average.
* Apple rose 2.1 percent to $101.85 in heavy premarket trading a day after it reported revenue that topped expectations, helped by strong sales of its iPhone line. It also gave a strong outlook for the holiday quarter.
* Chipmaker Texas Instruments also posted revenue that beat forecasts, easing concerns about weak industry demand following IBM's results.
* The results gave an outsized lift to futures in the tech-heavy Nasdaq index. With 16 percent of S&P 500 companies having reported so far this quarter, 62 percent have topped earnings expectations, according to Thomson Reuters data.
* Dow components Coca-Cola Co, Verizon Communications Inc, McDonald's Corp and Travelers Co are all scheduled to report results on Tuesday.
* Despite the strength in earnings, concerns continue to swirl over the pace of global economic growth. An index of shares in China fell 0.7 percent after the country's gross domestic product grew 7.3 percent in the third quarter, the slowest pace since the first quarter of 2009, during the financial crisis.
Futures snapshot at 6:44:
* S&P 500 e-minis were up 10 points, or 0.53 percent, with 245,063 contracts changing hands.
* Nasdaq 100 e-minis were gaining 26.25 points, or 0.68 percent, in volume of 39,011 contracts.
* Dow e-minis were up 61 points, or 0.37 percent, with 33,878 contracts changing hands. (Editing by Lisa Von Ahn)