Boston-based buyout firm Berkshire Partners has agreed to pay $2 billion to acquire Lightower Fiber Networks and Sidera Networks and then merge the two companies to form a fiber-optic network operator serving 6,000 locations.

Boxborough, Massachusetts–based Lightower and New York–based Sidera both provide commercial clients such as data centers and financial exchanges with fiber-based communications networks that offer access to the Internet and private networks as well as cloud-storage and data-center services. Once Berkshire merges the two companies, their combined network will serve 6,000 locations and cover 20,000 miles in the Northeast, Mid-Atlantic, and Midwest regions.