Amazon Fulfillment Services and Air Transport Services Group announced an agreement to operate an air cargo network serving Amazon customers in the U.S.

Amazon will lease 20 Boeing 767 aircraft from ATSG’s Cargo Aircraft Management business for five to seven years. The aircraft will be operated by ABX Air and Air Transport International airlines, both of which are subsidiaries of ATSG. ATSG is a provider of aircraft leasing and air cargo transportation services.

“Since last summer, we have been working closely with Amazon to demonstrate that a dedicated, fully customized air cargo network can be a strong supplement to existing transportation and distribution resources,” said Joe Hete, president and CEO of ATSG. “We are excited to serve Amazon customers by providing additional air cargo capacity and logistics support to ensure great shipping speeds for customers.”

As part of the deal, Amazon has also agreed to acquire up to 19.9% of ATSG. Amazon is making the move to improve its capacity to support shorter shipping times for prime customers. This is also seen as the start of Amazon trying to grow its logistics network and gain more control over its shipping costs and delivery times, according to a Bloomberg Report.

In a similar move late last year, the company purchased thousands of trailers to keep up with shipping demand and increase its capacity to deliver goods.

“We’re excited to supplement our existing delivery network with a great new provider, ATSG, by adding 20 planes to ensure air cargo capacity to support one and two-day delivery for customers,” said Dave Clark, Amazon senior vice president of worldwide operations and customer service.