(Reuters) - FedEx ( FDX ) said on Thursday it has invested in AI robotics and autonomous technology company Nimble to help scale up the delivery giant's Fulfillment unit which aids small and medium-sized businesses in fulfilling orders and managing inventory.

Parcel delivery companies are ramping up investments in automation in an effort to cut down costs and boost efficiency at a time when freight demand remains subdued.

FedEx ( FDX ) said the investment would help streamline its supply chain capabilities across North America, through Nimble's automated third-party logistics solutions.

"Our strategic alliance and financial investment with Nimble expands our footprint in the e-commerce space, helping to further scale our FedEx Fulfillment offering across North America," said Scott Temple, FedEx Supply Chain president.

The companies did not disclose the size of the investment.