US STOCKS-Wall St set to open mixed on tepid data

* April retail sales unchanged from March

* Import prices fall for 10th straight month

* Macy's, Ralph Lauren down after results

* AmEx, Delta rise on buybacks, dividend hikes

* Futures: Dow down 6 pts, S&P up 2.50 pts, Nasdaq up 11 pts (Adds details, comment, updates prices)

By Tanya Agrawal

May 13 (Reuters) - U.S. stock index futures pointed to a mixed open on Wednesday after data showed that the U.S. economy was struggling to make a strong rebound after meager first-quarter growth.

U.S. retail sales were unchanged in April as households cut back on purchases of automobiles and other big-ticket items.

Import prices fell for a 10th straight month in April, while weekly applications for home mortgages were down as interest rates rose to the highest level since March.

"The data puts into question the Fed's notion that the weak first-quarter data was transitory," said Adam Sarhan, chief executive of Sarhan Capital in New York.

"The underlying conversation in the market is that the economy has to eventually stand on its own two feet. So when will the patient be strong enough to get off the medicine?"

S&P 500 e-mini futures were up 2.5 points and their fair value - a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract - indicated a higher open.

Dow Jones industrial average e-mini futures fell 6points and Nasdaq 100 e-mini futures added 11 points.

U.S. stocks closed down for the second straight day on Tuesday on a global bond rout.

Macy's fell 1.3 percent to $64.50 after reporting a fall in quarterly profit, hurt by lower foreign tourist spending in the United States, colder-than-usual weather in February and disruptions at West Coast ports.

Ralph Lauren fell 4 percent to $128.87 after warning that a strong dollar would hurt full-year sales.

Shares (Frankfurt: DI6.F - news) of pipeline company Williams Partners LP jumped 23.8 percent to $58.70 in premarket trading after Williams Cos said it would buy its affiliate for about $13.8 billion.

Owens-Illinois rose 9.2 percent to $26 after the glass container maker said it would buy the food and beverage glass container business of Mexico's Vitro SAB de CV for $2.15 billion.

Delta Airlines rose 2.4 percent to $47.20 after it announced a $5 billion buyback program and raised its quarterly dividend to 13.5 cents per share from 9 cents, while Dow component American Express (Swiss: AXP.SW - news) rose 1.6 percent to $80.35 after it hiked its dividend by 12 percent.

Earnings expected before the close include Shake Shack (NYSE: SHAK - news) , J.C. Penney and Cisco. (Editing by Saumyadeb Chakrabarty)