A Biddeford internet provider plans to expand broadband networks in five Maine communities, including parts of South Portland.

Great Works Internet Partners, or GWI, said Monday that it intends to install 240 miles of fiber-optic cable in Millinocket, East Millinocket, Medway, Belfast and South Portland beginning in a few months.

The broadband expansion will reach 12,000 homes and businesses, the company said in a news release. Construction should be completed by early 2023.

“When it comes to the needs of residents, there is a growing demand for bandwidth on a daily basis, and our goal is to provide universal and ubiquitous service for all,” said GWI President Karem Durdag in a statement. “Fiber infrastructure plays a vital role in addressing these challenges for the long term.”

Funding for the $9.5 million buildout in South Portland and Belfast was provided by Arctaris Impact Investors, a Boston firm that also financed the reopening and operation of Saddleback Mountain ski resort near Rangeley in 2019.

The Finance Authority of Maine, a public financing agency also known as FAME, provided a 20 percent loan insurance on the Arctaris investment. FAME also provided a $1 million direct loan for post-construction costs in Belfast and South Portland.

Parts of the new fiber-optic network will be installed in “opportunity zones” – areas of the state designated to give investors special tax benefits. Thirty-two zones were created in Maine through the 2017 Republican tax cut. Capital gains – profits from the sale of investments – put into those areas receive generous tax breaks.

Millinocket, East Millinocket and the Maine Mall area of South Portland are opportunity zones.

The new fiber-optic networks come as Maine and other states move ahead with plans to invest at least $250 million in federal funding for high-speed internet service.

Up to 83,000 households in the state lack access to broadband, according to state estimates. Since the pandemic, connecting to reliable, fast internet service has become more crucial for education, healthcare, social connections and commerce.

“Today, more than ever, equitable access to affordable, high-speed internet is crucial to the economic viability of cities and states throughout our country,” said Arctaris Principal Neil Katz in a statement. “By building fiber-based broadband networks, we are developing the infrastructure necessary to lessen the digital divide in underserved communities.”