(Reuters) - FedEx 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 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.

(Reporting by Pratyush Thakur in Bengaluru; Editing by Janane Venkatraman and Krishna Chandra Eluri)