A FedEx delivery worker carries a package for a delivery in Wilmette, Illinois, in this October 27, 2015, file photo. REUTERS/Jim Young/Files

(Reuters) - Shares of U.S. delivery services company FedEx Corp FDX.N could rise another 15 to 20 percent over the next year after soaring 12 percent on Thursday, Barron's reported on Sunday.

Even with last week's gain, the stock has fallen about 8 percent over the last nine months, due in part to worries that Amazon.com AMZN.O was looking to enter the delivery business, the financial paper said.

FedEx shares closed at $163.71 on Friday.

Amazon was reportedly negotiating to lease 20 jets from Boeing Co BA.N in December.

But analysts think Amazon will probably use the planes to shift merchandise among its distribution centers, Barron’s said.

FedEx said on its earnings call last week that no customer accounted for more than 3 percent of revenue for any of its businesses, including express, ground and freight, much lower than many analysts had assumed, Barron’s said.

FedEx also said more retailers were shipping to homes from stores, rather than from distribution centers, Barron’s noted. That plays into FedEx’s strength in having a vast driver network, it said.

FedEx has historically traded at a discount to rival United Parcel Service Inc UPS.N, Barron's said, because ground is a more lucrative business than express and FedEx is an express specialist.

But FedEx’s recent discount of 23 percent to UPS compares with an average of 13 percent over the past decade, Barron’s said, noting that the gap is expected to grow smaller.