Amazon.com Inc. said Wednesday it is ordering 20,000 Mercedes-Benz vans from Daimler AG as part of a broad plan to build out its delivery fleet and have small businesses carry an excess supply of packages.
The online retail giant in June said it would for the first time invite entrepreneurs create delivery companies, each employing as many as 100 drivers and leasing between 20 and 40 vans emblazoned with Amazon’s logo.
Amazon...