Futures wobble; Macy's slides on earnings; Deere up

U.S. stock index futures signaled a lower open Wednesday amid conflicting economic signals and what they will mean for monetary policy.

While investors have been anticipating the Federal Reserve will begin unwinding its monthly bond purchases as soon as September, economic data indicated that inflation, at least, is of little concern.

Producer prices excluding food and energy rose just 0.1 percent in July, while including those items put the index at flat.

Data Tuesday showed U.S. retail sales rose by half a percent in July, their fastest pace in seven month, keeping talk alive that the Federal Reserve may begin tapering its asset purchases following the central bank's September meeting.

Markets have greeted positive growth with mixed emotions as it serves as a further harbinger that historically easy monetary conditions are winding down.

In company news, Apple shares gained 1 percent in premarket trading, a day after activist investor Carl Icahn revealed he had taken a large stake in the company.

Deere shares also got a nice bump after it reported strong earnings of $2.56 a share, easily beating Wall Street expectations. Early trading put the stock up about 1 percent.

On the downside, Macy's whiffed on earnings, posting a profit of 72 cents a share that missed estimates by 6 percent. Guidance also was weak, sending shares sliding 3.4 percent.

Dow component Cisco will report after Wall Street closes.

UPS suffered a tragedy after one of its cargo planes crashed in Alabama, killing the pilot and co-pilot.

Investors will be watching the release of 13F regulatory reports that show where the biggest managers have been putting their money.

The latest look at mortgage applications from the Mortgage Bankers' Association showed a drop of 5.4 percent. The Energy Department's assessment of oil and gasoline inventories at 10:30 a.m.

In Europe, data out on Wednesday showed the euro zone expanded by 0.3 percent in the second quarter, quarter-on-quarter, marking an end to the region's recession.

Earlier in the day, Germany and France posted forecast-beating growth for the second quarter. Germany's economy grew by 0.7 percent, as domestic public and private consumption picked up, while France leaped out of recession, posting 0.5 percent growth.

"The euro zone still has a long way to go before positive growth numbers can honestly be called recovery, but relief should stand above skepticism, at least for one day," said Carsten Brzeski, senior economist at ING.

In Asia, Japanese stocks hit a one-week high and South Korea's Kospi index rose to a one-and-a-half week high, but the Shanghai Composite and Australia's S&P ASX 200 closed lower.

Later in the day, traders will closely scrutinize a speech by St. Louis Federal Reserve President James Bullard. It follows a talk by Atlanta Fed President Dennis Lockhart on Tuesday which downplayed the notion that the central bank would begin winding down its stimulus program in September.

Meanwhile, the Fed will purchase $1.25-$1.75 billion of 23-40-year Treasury notes on Wednesday.

—By CNBC's Katy Barnato