"This change is consistent with our strategy to focus on the broader e-commerce market, which the recent announcements related to our FedEx Ground network have us positioned extraordinarily well to do," a FedEx spokesperson said.
Shares of FedEx and Amazon were down at least 1% in premarket trading. Bloomberg first reported FedEx's decision.
"We are constantly innovating to improve the carrier experience and sometimes that means reevaluating our carrier relationships," an Amazon spokesperson said. "FedEx has been a great partner over the years and we appreciate all their work delivering packages to our customers."
FedEx announced in June that it is ending its express U.S. shipping contract, which only affected air services. At the time, FedEx said it was a "strategic decision" that would not affect its other contracts with Amazon. At the time, FedEx said less than 1.3% of total revenue was attributable to Amazon during the 12-month period ended Dec. 31.
Dave Clark, senior vice president of worldwide operations at Amazon, said in a tweet that he had "nothing but respect" for FedEx and called the move "conscious uncoupling at its finest."
Amazon has continued to increase its own delivery network.
In late June, Amazon announced a Delivery Service Partners program in an effort to attract entrepreneurs who can create their own local delivery networks with up to 40 vans each. earlier that month, it debuted a delivery drone it hopes will eventually speed up delivery for Prime members in North America.
Amazon also has a $1.5 billion hub opening in northern Kentucky in 2021 where it's expanding its Amazon Air fleet to include 50 planes. Amazon said its air network can make "two-day shipping possible almost anywhere in the U.S." Still, FedEx has helped to provide the "last mile" of delivery services, bringing packages to customer doors.
FedEx said in May it would expand its ground-delivery service to run seven days a week starting in January.