U.S. stock index futures point to a mixed opening Friday as investor sentiment remained fragile following concerns about the worsening debt crisis situation in the euro zone to hurt global economic growth.

Futures on the Dow Jones Industrial Average were down 0.10 percent, futures on the Standard & Poor's 500 index were down 0.20 percent and futures on the Nasdaq 100 index were up 0.10 percent.

The ongoing political and policy uncertainty stemming from the euro zone debt crisis is expected to loom over markets Friday. The euro zone finance ministers will have Friday the Eurogroup meeting in Brussels, in which they are expected to formally approve an agreement to lend 100 billion euros ($122 billion) to Spain for recapitalizing its banks.

At the same time, investors' confidence is getting dampened by mounting the debt pressure on the euro zone. Market players are worried that Spain is facing a rising borrowing cost with its 10-year government bond yields soaring to over 7 percent. Investors are also concerned that the contagion will spread to Italy, which is faced with increasing burden of debt.

On Thursday, the U.S. markets rose as investor sentiment continued to be lifted by better-than-expected earnings from companies undermining worrying indications of weakness in the economy. International Business Machines Corp reported that its second quarter operating net income rose to $3.51 per share up from $3.09 per share in the same period earlier year.

The Dow Jones industrial average rose 0.27 percent, the S&P 500 Index advanced 0.27 percent and the Nasdaq Composite Index was up 0.79 percent.

Major European indices fell as investor confidence was down following increasing pressure of borrowing costs on the euro zone. London's FTSE 100 was down 9.26 points, Germany's DAX 30 index fell 5.20 points and France's CAC 40 declined 4.94 points.

Asian stocks also made losses following global cues. Market sentiment was negative amid worries of the deepening debt burden faced by the euro zone and worsening global economic growth.