U.S. stock index futures indicated a modestly higher open on Friday as positive remarks from Treasury Secretary Timothy Geithner supported optimism for a recovery, but Wall Street could stall after five days of gains.

Underscoring optimism the global economy is pulling out of its slump was surprisingly strong industrial output and other economic data from China.

Geithner said on Thursday that with a strengthening economy the government can end some of the extraordinary support put in place for markets and prepare for a slow recovery.

Appearing before the Congressional Oversight Panel for the $700 billion Troubled Asset Relief Program, Geithner said the economy was in far better shape now than a year ago when it was on the verge of collapse, though it still had problems.

The general economic recovery -- which you get more and more testimony on everyday -- is causing investors to rebuild equity portfolios and continue to buy stocks, said Rick Meckler, president of investment firm LibertyView Capital Management in New York.

Geithner only helped support that idea that things in general are improving and it has led to a period of a very sustained rally.

But stocks could be ripe for profit taking after racking up five days of gains on Thursday, the longest winning streak since November.

S&P 500 futures rose 1.70 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 gained 1 point, and Nasdaq 100 futures added 5.25 points.

Data on tap includes the Reuters/University of Michigan Surveys of Consumers preliminary September consumer sentiment index at 9:55 a.m. EDT. Economists in a Reuters survey expect a reading of 67.3 compared with 65.7 in the final August report.

Investors have been looking for any signs of life from the consumer as anemic spending remains one of the biggest challenges facing a strong recovery.

Morgan Stanley Chief Executive John Mack is stepping down and will be replaced by retail brokerage head James Gorman as the bank embraces stable businesses after losing big on risky ones.

National Semiconductor Corp slipped 1.7 percent to $15.70 in premarket trading after the chipmaker reported better-than-expected first-quarter results. National Semi's stock has gained more than 30 percent in the past two months.

Shares of American International Group Inc tumbled 2.9 percent to $38.75 before the bell after Wells Fargo Securities downgraded the insurer to underperform. The brokerage said AIG has virtually no tangible book value at the moment and that its shares are overpriced.

(Reporting by Leah Schnurr; editing by Jeffrey Benkoe)