Amazon's third-party merchants are now barred from using FedEx Ground for Prime shipments

Third-party vendors were told by Amazon over the weekend that they are barred from using FedEx’s ground delivery services for Prime shipments. The Wall Street Journal reports that a message sent by Amazon to merchants on Sunday said the ban will last "until the delivery performance of these ship methods improves." The e-commerce platform will still allow FedEx Ground for non-Prime shipments and FedEx Express, a faster but pricier option, for Prime.

Third-party sellers now account for more than half the products sold on Amazon.com and the company’s decision on FedEx’s ground delivery comes during the peak of the holiday shopping season. Over the summer, FedEx ended partnerships with Amazon to provide it with express air deliveries and ground shipments.

An Amazon spokesperson said that the company is managing cutoffs for delivery by Christmas and wants to ensure that customers receive their packages on time. TechCrunch has also contacted FedEx for comment.

Both FedEx and UPS experienced recent shipping delays, which they said were caused by record shipping volumes and weather issues.

Amazon has also been under scrutiny by federal antitrust regulators, with some complaints centered on whether or not it forces sellers to rely on its own logistics network. The company’s focus on its warehouse and delivery services, combined with its status as the largest online retailer in the U.S., has turned it into a major competitor against FedEx, UPS and the United States Postal Service.

A recent Morgan Stanley report estimates that Amazon is currently delivering about 46% of the items ordered through its U.S. site and predicts Amazon Logistics will not only start providing shipments for non-Amazon orders, but overtake FedEx, UPS and the USPS in shipment volume by 2022.