* Futures up : Dow 56 pts, S&P 9.25 pts, Nasdaq 20.75 pts
By Abhiram Nandakumar
Sept 29 (Reuters) - U.S. stock index futures were up on Tuesday, a day after concerns about waning demand from China and a selloff in health care shares rattled investors and added to the uncertainty around the timing of a U.S. interest rate increase.
* Global stocks fell to their lowest in more than two years, reeling under pressure from weak raw material prices.
* Goldman Sachs said it expects sales growth for S&P 500 companies in aggregate to shrink this year for the first time in five years, hurt by slowing global growth and lower oil prices.
* The S&P 500 and the Nasdaq Composite Index have closed down for the past five sessions.
* The Nasdaq Biotechnology Index and the S&P 500 health care index fell for the seventh straight day, closing down more than 3.4 percent.
* Investors will be closely watching data expected to be released this week, culminating in nonfarm payrolls numbers on Friday, for clues on the health of the U.S. economy.
* A number of Federal Reserve officials are scheduled to speak at events this week, but mixed opinions on the timing of a rate hike is likely to add to investor jitters.
* Fed Chair Janet Yellen has said the central bank is on track to raise rates for the first time since 2006, with New York Fed President William Dudley saying the hike could come as soon as next month.
* But Charles Evans, head of the Chicago Fed, took a far more dovish view, calling for rates to stay near zero until mid-2016.
* Billionaire investor activist Carl Icahn was the latest to criticize the U.S. Federal Reserve's inaction on interest rates, warning about the unintended consequences of ultra-low interest rates on the economy and financial markets.
* Data being released on Tuesday includes consumer confidence for September, which is expected to have fallen to 96.1 from 101.5 last month. The data is expected at 10:00 a.m. ET (1400 GMT).
* U.S. companies reporting quarterly earnings on Tuesday include Costco and Diamond Foods.
* Yahoo shares rose 3.4 percent to $27.60 premarket on Tuesday, a day after the Internet company's board decided to proceed with spinning off Alibaba stake.
* Republic Airways was up 6 percent at $5.29 premarket after Deutsche Bank raised the stock to "buy" and the airline reached agreement on new contract with its pilots.
Futures snapshot at 7:15 a.m. ET (11:15 GMT):
* S&P 500 e-minis were up 9.25 points, or 0.49 percent, with 283,004 contracts traded.
* Nasdaq 100 e-minis were up 20.75 points, or 0.51 percent, on volume of 53,852 contracts.
* Dow e-minis were up 56 points, or 0.35 percent, with 48,919 contracts changing hands. (Reporting by Abhiram Nandakumar in Bengaluru; Editing by Saumyadeb Chakrabarty)