NEW YORK (MONEY) -- Global economic growth is providing the air beneath the wings of FedEx, the leading air express shipper.

The company's earnings reports have beaten analysts' estimates. And the share price has risen by about 10 percent since I last recommended the stock in December.

FedEx reported excellent results last week for the fourth fiscal quarter ended May 31. The company also painted a bright picture for the rest of this year and the next fiscal year.

For the most recent quarter, FedEx reported a 25 percent increase in operating income on a 10 percent increase in revenues.

Operating profit margins also improved. And net income beat analysts' projections by 5 cents a share. Results for the full year were similarly positive. Three of FedEx's businesses are thriving: Quarterly operating income was up 30 percent for the Express division; 20 percent for ground shipment; and 49 percent for freight.

The only major disappointment was Kinko's, the copying and business-services company that FedEx acquired in 2004. For the most recent quarter, Kinko's revenues were off slightly and operating income was down by 56 percent.

One factor helping FedEx's overall results is that the company has a policy of fuel surcharges on its shipping fees, which allows FedEx to pass the effects of high oil prices through to customers.

So far, at least, these surcharges -- which often amount to more than 10 percent of the shipping cost -- have met with relatively little customer resistance.

FedEx has estimated results for the current quarter that top consensus estimates. The company has also projected solid growth for the rest of this fiscal year and next.

Besides an expanding global economy, FedEx should be helped by capital investment. For the current fiscal year, the company plans to spend $2.9 billion, three-quarters of which will go to fund growth.

In May, FedEx (Charts) announced an agreement to acquire Watkins Motor Lines for $780 million, which should boost the freight division's profits.

And at Kinko's, FedEx continues to spend on opening new locations, refurbishing stores and retraining workers. At some point within the next couple of years, those efforts should begin to contribute to the bottom line.

Annual earnings are projected to grow at a compound rate of as much as 15 percent over the next five years. That would be faster than the sector, which in turn has better growth prospects than the S&P 500.

Yet despite excellent recent results and superior long-term prospects, FedEx shares at $115 are trading at less than 17 times estimated earnings for the fiscal year that has just begun -- seems like the stock should be cruising at a higher altitude.

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Michael Sivy is an editor-at-large for MONEY Magazine. Sivy on Stocks runs each Tuesday at CNNMoney.com -- sign up to receive it by e-mail.