Stock index futures fell on Friday after China surprised global markets by increasing banks' reserve requirements, raising worries about the impact of eventual monetary tightening on global growth.

The hike in reserve requirements comes on the heels of a similar increase last month and raised worries that the pace of monetary tightening in China could be more swift than had been expected.

The news boosted the U.S. dollar, dragged European shares lower and pressured commodity prices, which could weigh on resource stocks. Crude oil futures fell about 2 percent to $73.78 a barrel, while Chevron Corp fell 1.4 percent to $70.75 before the opening bell.

The reason the market is spooked by China is to some extent, as we look here in the United States to cut back on some of the stimulus, we're almost counting on other nations to continue to provide the same level of demand, said Rick Meckler, president of investment firm LibertyView Capital Management in New York.

Seeing China possibly cut back at the same time is raising concerns about whether or not we can come out of this with the same level of demand.

Overseas developments have been the main focus of U.S. equity markets in recent weeks on growing concerns about the heavy debt loads of some euro zone nations. A pledge by European leaders on Thursday to support debt-laden Greece eased fears of a broader euro zone crisis and helped lift U.S. stocks.

S&P 500 futures fell 7.8 points and were below 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 lost 71 points and Nasdaq 100 futures slipped 13.25 points.

Investors will take in a round of data, including some that had been rescheduled from earlier in the week because of heavy snow in Washington. U.S. retail sales for January are due at 8:30 a.m. (1330 GMT). Core retail sales -- excluding autos, gasoline and building materials -- are expected to rise 0.3 percent after a fall of 0.3 percent in December, according to Reuters data.

December business inventories are on tap at 10 a.m. and are expected to rise 0.2 percent. A preliminary reading of the Reuters/University of Michigan consumer survey is scheduled for 9:55 a.m. and is expected to rise to 75.

Ingersoll-Rand Plc reported results that missed analysts' expectations as weak nonresidential construction hit demand for heating and cooling systems.

Credit Suisse started Dow component Procter & Gamble Co
with an outperform rating and a target price of $74.

(Editing by Padraic Cassidy)