New York - US stock index futures fell on Friday, setting up Wall Street for its first weekly decline since mid April, amid concern the central bank may scale back its support to the economy.

Trading has been choppy in the second half of the week as market participants assess the Federal Reserve's evolving stance towards markets. Fed support has been instrumental in a rally that has boosted US stocks to record highs this year.

Since Wednesday, the markets have been focused on the possibility of Fed purchases being scaled back later this year, in the wake of congressional testimony by Fed Chairman Ben Bernanke and the minutes from the latest Federal Open Market Committee meeting.

“Markets are looking for a reset and a retracement lower, closer to more compelling valuations,” said Peter Kenny, chief market strategist at Knight Capital in Jersey City, New Jersey.

He said on Wednesday there was a shift that “reintroduced a sense of caution that has long been absent” in markets.

The minutes showed a degree of fracture in the FOMC “in terms of the approach moving forward, specifically the time frame” of the unwinding of the Fed's stimulus efforts.

S&P 500 futures fell 7 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 fell 43 points, and Nasdaq 100 futures lost 14 points.

Procter & Gamble shares rose 3.4 percent in premarket trading, a day after the world's largest household products maker brought back A.G. Lafley as chief executive, replacing Bob McDonald in the midst of a major restructuring.

The Commerce Department will release April durable goods orders data at 8:30 a.m. EDT (14:30 SA time).

Economists in a Reuters survey expect a 1.5 percent rise, compared with a 6.9 percent drop in orders in March.

Abercrombie & Fitch shares dropped 12 percent in premarket trading after the teen clothing retailer said quarterly comparable sales fell 15 percent, which it blamed in part on inventory shortages.

Shares of Sears Holdings tumbled 14.5 percent in light premarket trading after the US retailer reported a bigger-than-expected quarterly loss on Thursday, hurt by cooler spring weather.

Pandora Media shares jumped 13 percent in premarket trading after the streaming music service said Thursday first-quarter revenue grew on the strength of mobile advertising. At least five research firms raised their price target on the stock. - Reuters