Stock index futures were little changed on Friday as a pullback in commodity prices weighed on natural resource shares as the U.S. dollar rebounded.

The dollar rose broadly after Federal Reserve Chairman Ben Bernanke said that monetary policy might have to be tightened as a recovery takes hold.

The dollar's decline, which culminated in a 14-month trough against a basket of currencies on Thursday, has been one the major underpinnings of the stock market's run-up as the appetite for riskier assets grew.

Among mining shares, Freeport-McMoran Copper & Gold Inc slipped 0.3 percent to $74.79 before the bell, while Newmont Mining Corp dropped 0.7 percent to $46.70. In the energy sector, shares of ConocoPhillips fell 0.7 percent to $51.01.

If the dollar remains up a bit throughout the day, you'll probably see a bit of a pullback, some profit-taking in the market, said Matt McCall, president of Penn Financial Group in Ridgewood, New Jersey. Especially with a lack of any big news, attention falls back to the U.S. dollar and to expectations of earnings for next week.

S&P 500 futures dipped 2.7 points but were a tad 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 shed 13 points, and Nasdaq 100 futures fell 6.5 points.

U.S. front-month crude slipped 35 cents to $71.34 a barrel, while gold eased after hitting records for three straight sessions.

But shares of Research In Motion Ltd , a maker of BlackBerry devices, rose 1.4 percent to $69.60 following a broker upgrade.

U.S. stocks rose for a fourth straight session Thursday as a surprising quarterly profit from aluminum company Alcoa Inc got third-quarter earnings off to a strong start.

The benchmark S&P 500 <.SPX> has rallied nearly 60 percent from a 12-year low of early March.

(Reporting by Ellis Mnyandu; editing by Jeffrey Benkoe)