FedEx Corp. is ending its contract to deliver Inc. packages through its ground network.

FedEx announced it decided not to renew the contract when it expires at the end of August. The decision signifies a cutting of ties with one of the world's biggest shippers.

In June, FedEx said it was ending its air-shipping contract with Amazon in the U.S. but would continue to handle ground deliveries. FedEx would still handle international shipments.

Amazon is in the process of developing its own delivery network, including leasing cargo planes, buying trucks, and funding local delivery drivers, leading to escalating tensions between the longtime partners.

Though it is abandoning its partnership with the largest e-commerce business in the U.S., FedEx is positioning itself as a go-to carrier for Target Corp., Walmart Inc., and the world of retailers competing with Amazon.

“This change is consistent with our strategy to focus on the broader e-commerce market,” FedEx said in a statement.