Stock index futures fell on Friday on worries about the impact of heavy euro-zone debt loads on the global recovery, while investors were cautious ahead of retail sales data.

The initial optimism over moves this week to keep Greece's debt crisis from spreading appeared to be ebbing on fears that the efforts won't be enough, and that plans to reign in national budgets could stifle growth.

The jitters took the euro to an 18-month low against the dollar, while gold hit record highs. Overseas, European shares <.FTEU3> fell nearly 2 percent.

One of the misnomers is that the 750 billion euro ($1 trillion) program and the austerity measures that are being forced for the loans are going to magically make these problems go away, and this is not true, said Jamie Cox, managing partner of Harris Financial Group in Colonial Heights, Virginia.

The contagion threat has been dealt with, but the debt problems of these countries have been there for decades, and they're not going away overnight.

Shares of Nvidia Corp fell 4.4 percent to $14 a day after the graphics chipmaker forecast sales below Wall Street's target.

Consumer data on tap includes April retail sales at 8:30 a.m. EDT and May preliminary consumer sentiment at 9:55 a.m. EDT. Retail sales are expected to rise 0.2 percent, compared with a gain of 1.9 percent the month before, while the consumer sentiment reading is expected at 73.5, compared with 72.2 in the previous month, according to a Reuters poll of economists.

S&P 500 futures fell 11.2 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 67 points, and Nasdaq 100 futures shed 16.25 points.

Outlooks from retailers did little to inspire confidence in the consumer. J.C. Penney Co Inc reported higher quarterly profit Friday, but gave a modest profit forecast.

On Thursday, two other department store chains serving different markets, Kohl's Corp and Nordstrom Inc , reported double-digit profit growth, but their forecasts indicated concerns about consumer spending.

Other economic data will include April industrial production at 9:15 a.m. EDT and March business inventories at 10 a.m. EDT. Production is expected to rise 0.6 percent from 0.1 percent the month before, and business inventories are forecast to rise 0.4 percent, compared with 0.5 percent.

Energy shares could come under pressure as oil futures fell 1.7 percent to $73.16 a barrel amid swollen crude inventories and jitters about the European debt crisis.

Stocks fell on Thursday after downbeat comments about the economy from Cisco Systems Inc , the big maker of computer routers and switches, and Kohl's.

(Editing by Jeffrey Benkoe)

Retail sales