In a dramatic reversal, Verizon and the City of Boston are set to announce an expansion of the telecom company’s much sought-after FiOS service to the Hub, starting in Dorchester, West Roxbury, and Roxbury’s Dudley Square.

“Boston is moving faster than our current infrastructure can support, and a modern fiber-optic communications platform will make us a next-level city,” Mayor Martin J. Walsh said in a statement.

Verizon will spend $300 million over six years, a statement says.

“This transformation isn’t just about advanced new fiber-optic technology — it’s about the innovative services this platform will allow people to create and use, today and in the future,” Verizon Wireline Network president Bob Mudge said in a statement.

Many Boston businesses and residents had long lobbied for Fios in Boston, where Comcast has had a virtual monopoly on internet access for years.

The announcement comes six months after representatives for the company explicitly told the Boston City Council that Verizon had no plans to expand FiOS to any additional cities.

Walsh’s administration has been pushing and advocating for faster and better internet service since he took office.

DEVELOPING…