Berkshire Partners has finalized a $2 billion merger that combines Lightower Fiber Networks and Sidera Networks. Both companies had been PE-backed. Lightower is a Massachusetts-based metro fiber and bandwidth provider that had been owned by Ridgemont Equity Partners, Pamlico Capital and M/C Partners. Sidera, based in New York, provides communications services to large enterprise, carrier and data center customers and had been backed by ABRY Partners and Spectrum Equity Investors. The combined company operates a fiber-based network throughout the Northeast, Mid-Atlantic and Midwest, providing access to more than 6,600 on-net locations, including commercial buildings, data centers, financial exchanges, content hubs and other critical interconnection facilities. Pamlico and ABRY will remain as investors in the new entity.