Uber Freight was launched in 2017 as the shipping arm of Uber Technologies, the parent of the ride-hailing and food-delivery companies.
The freight service enables trucking companies and drivers to book loads just as they would book Uber rides, a company statement says.
Greenbriar is the Rye, N.Y., private-equity firm focused on logistics, transport, manufacturing and more.
Uber Freight said it planned to use the funds to build out its logistics platform and speed new products to market.
As part of the investment, Greenbriar Managing Partners Michael Weiss and Jill Raker will join the Uber Freight board. Uber will retain majority control of the freight unit.
Greenbriar is "a partner with deep expertise and a shared passion for simplifying logistics," said Uber Freight head Lior Ron.
The transaction is expected to close this month, subject to customary conditions. The statement didn't specify them.
Greenbriar's people have "decades-long involvement in the logistics sector," Weiss said in the statement.
Ron said Uber Freight's technology has "[transformed] dated and analog processes to ensure that both shippers and carriers are equipped to succeed in a rapidly changing industry."
Uber Freight's funding deal with Greenbriar follows other recent moves the company has made, including forming new integration partnerships with large cloud-service providers, and expanding its enterprise-software offering with the launch of Uber Freight Enterprise and Uber Freight Link.
On a day when the broad market is indicated lower, Uber shares at last check were off 3% at $36.04.