* Netflix and Texas Instruments rally on results
* DuPont and Travelers raise quarterly dividends
* Chinese factory data raises growth concerns
* Dow up 41 pts, S&P up 3 pts, Nasdaq up 11.25 pts
By Ryan Vlastelica
NEW YORK, April 23 U.S. stock index futures edged higher on Tuesday as strong earnings improved sentiment, but weak data from China underlined concerns about global growth.
* Equities have steadily advanced in 2013, leading many analysts to predict a correction in the market, although major indexes have rebounded off declines. Still, a mixed earnings season and data pointing to weakness have raised questions about whether the rally will continue.
* In China, data showing little growth in factory activity was the latest indicator that global growth may come under pressure. Last week discouraging economic data from China contributed to a massive drop in commodity prices.
* Nasdaq futures were lifted a day after both Netflix Inc and Texas Instruments Inc reported strong results. Texas Instruments also said that improving demand for its chips would lead to growth in the current quarter. Its shares were up 0.8 percent to $35.10 before the opening bell.
* Netflix soared 24 percent to $216 in premarket trading after the company reported earnings that beat expectations and strong subscriber growth.
* DuPont reported adjusted first-quarter earnings that beat expectations and raised its quarterly dividend. Travelers Cos Inc, which along with DuPont is a Dow component, also raised its quarterly dividend.
* S&P 500 futures rose 3 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures added 41 points and Nasdaq 100 futures rose 11.25 points.
* Investors will be watching the S&P's 50-day moving average of 1,544.96. If the index falls below that level, as it did last week, it could be another sign that the rally is stumbling.
* Earnings season has been largely positive, with more than 67 percent of S&P 500 companies that have reported beating expectations, according to Thomson Reuters data. Still, there have been a number of high-profile disappointments, including from IBM and General Electric Co
* Analysts see earnings growth of 2.1 percent this quarter, up from expectations of 1.5 percent at the start of the month. Apple Inc, Illinois Tool Works and AT&T Inc are due to report Tuesday.
* U.S. stocks rose on Monday, rebounding from steep losses in the previous week. Microsoft Corp helped lift the Nasdaq as an activist investor took a stake in the company.