New York (CNN Business) Amazon's go-it-alone delivery strategy has driven away one of its biggest partners. FedEx will end its ground delivery contract with Amazon.

Amazon AMZN For years, Amazon has used FedEx's ground delivery service to help shuttle online orders to consumers. Butis also rapidly bolstering its own delivery network, agitating established logistics businesses.

FedEx FDX announced Wednesday that it plans to let their ground ship contract expire at the end of the month. The company said in a statement that recent steps to bolster its delivery network have positioned the company "extraordinarily well" to "focus on the broader e-commerce market."

FedEx also dumped Amazon from its air cargo services in June. The company said at the time it would continue serving online shoppers through its partnerships with other companies not named Amazon. FedEx noted Amazon accounted for less than 1.3% of its total revenue in 2018.

"We are constantly innovating to improve the carrier experience and sometimes that means reevaluating our carrier relationships," an Amazon spokesperson said in a statement. "FedEx has been a great partner over the years and we appreciate all their work delivering packages to our customers."

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