(Adds CEO comments on trucking business, China unit, background)

MEMPHIS, April 11 (Reuters) - The U.S. economy is not growing at this point, but it is still unclear whether it is in recession, the top executive of package delivery company FedEx Corp <FDX.N> said on Friday.

"It's hard to tell whether the economy is skipping along the top of the waves or is just under water," Chief Executive Fred Smith told Reuters in an exclusive interview at FedEx's Memphis headquarters. "But there is no growth in the economy right now.

"The only positive story in the U.S. economy right now is U.S. exports."

Smith said that, if there is no significant run up in fuel prices in the months ahead, FedEx expects the economy may see some growth in the second half of this year.

"But the United States must become fuel efficient or it will be hard to restore any kind of long-term growth," he added.

Like its main rival, United Parcel Service Inc <UPS.N>, FedEx is considered a bellwether of U.S. economic health. Last month, FedEx reported a 7 percent decrease in quarterly earnings due to slowing U.S. economic growth and spiraling fuel costs. Earlier this week, UPS lowered its first-quarter earnings outlook, which it also attributed to deteriorating economic conditions and high fuel prices.

Although the U.S. trucking sector has been suffering because of the economic environment, FedEx expects its trucking unit to keep taking market share thanks to its on-time delivery performance of 98 percent to 99 percent -- compared with a sector average in the low 80s, Smith said.

FedEx's CEO said the company's Chinese domestic package service -- launched last year -- was "on trajectory" to meet internal profitability targets. He did not disclose those targets. (Reporting by Nick Carey; Editing by Andre Grenon)

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