Metronet has expanded its fiber network buildout to three million locations in the US.

The company, which was acquired by T-Mobile and KKR as part of a JV in July, announced the milestone this week.

The acquisition is a wider part of T-Mobile's fiber rollout strategy in the US. As part of the deal, Metronet has evolved into a wholesale builder and operator of fiber-optic networks used by T-Mobile Fiber.

“Metronet has built the strongest construction capacity in the industry, bringing world-class digital infrastructure to new cities at a pace that is unparalleled among pure-play fiber builders,” said Dave Heimbach, CEO, Metronet.

Metronet has significantly ramped up its fiber build-out in the last few years, serving more than 300 communities across 19 states.

The company noted that it took 17 years to reach its first million locations, but only two more years to hit the next million, and a little more than one year to surpass three million. By 2030, the ISP is aiming to reach 6.5 million homes.

Acquisitions have helped Metronet to increase this number, notably closing a deal to buy Minneapolis-based fiber ISP U.S. Internet (USI) in September. It was the company's seventh acquisition in seven years.

USI operates a 100 percent fiber network, which is accessible to more than 140,000 homes and businesses in and around Minneapolis.