Amazon has signed a $2.8 billion deal with a robotics firm to develop and commercialize a fleet of unmanned aerial vehicles that can deliver packages.

The deal, announced Tuesday, is the first major investment in Amazon’s unmanned delivery business.

The drones, known as Skybox drones, will provide Amazon with a toolkit to help automate and improve its logistics operations, said Mike Capps, a spokesman for Amazon.

The drones will also provide Amazon customers with more accurate shipping estimates.

Amazon also will sell the drones to private companies, such as FedEx and FedEx Express, which are trying to compete with Amazon in the delivery business, Mr. Capps said.

Amazon plans to use the drones for its own logistics activities.

The drone deal follows a $1.6 billion deal in January with a UAV provider that includes Amazon, UPS and FedEx.

Amazon says it has spent about $1 billion on the drones since they were introduced in December.

The agreement includes a five-year supply agreement with the drone provider and a $200 million, two-year commitment for Amazon to sell the Skybox drone.

Mr. Zaslavsky said the drones will be available to customers from the beginning of next year.

The contract is the latest sign of Amazon’s ambition to transform its delivery business by developing new products and services.

Last year, the online retailer began offering drones for delivery.

The company also launched its Amazon Flexible Delivery program, which lets customers take the delivery in a fleet-size box, a mini-bus, a pickup truck or a private van.

The company also began using drones to deliver packages at warehouses, a move that will help it cut costs and cut down on delays, which have led to a rise in package delays.