PORTLAND — Broadband digital service in the city is progressing, and may be on the cusp of a big leap forward.

Councilors on Monday heard updates from City Manager Jon Jennings, Finance Director Brendan O’Connell and representatives from Sifi Networks of America on how more than 30,000 homes and 4,500 city businesses could see marked increases in internet speeds.

“(It is) one of the most significant developments the city can anticipate in terms of economic growth,” Jennings said, adding it was a council goal for the year.

A memo from O’Connell and Information Technology Director Dan Boutilier notes the city’s fiber optic institutional network connecting municipal and school buildings was expanded this year to include the Canco Road buildings occupied by the Public Works Department and the Ocean Avenue Fire Station.

That expansion is a mere blip when compared to the proposals from SiFi Networks of America, which O’Connell said could bring high-speed broadband internet access to the city through an expanded fiber-optic network without any cost to city taxpayers.

“We are a fiber-optic network developer, an overall solution provider,” Sifi CEO Ben Bawtree-Jobson said Monday as he outlined potential options for a 2.5 million-foot fiber-optic network that could take 2 1/2 years to build.

Options for the city include a lease arrangement with Sifi, where user fees to the city would fund lease payments while still turning a profit for the city. O’Connell said the lease payments could be $5.3 million in the fifth year of a 30-year lease and $6.6 million by its final year. At the same time, revenues would grow from $5.3 million to $9.3 million.

Bawtree-Jobson said the network would be open to all internet service providers and would be built to accommodate future expansions.

“The infrastructure has to be built to last; this is very much a future-proof network,” he said.

It was estimated about 60 percent of the network could be built through “microtrenching,” a way of laying cable that is less invasive than traditional methods. The entire network would be underground.

Sifi Networks has set up similar fiber optic networks in Chattanooga, Tennessee, and Reykjavik, the capital of Iceland. Company data suggests the faster network could increase the city’s gross domestic product by 1.1. percent and home values by 3.1 percent, according to the presentation.

The city is also looking at alternative arrangements with Sifi Networks and could begin network construction in spring 2017 or 2018, depending on the business arrangement.

David Harry can be reached at 781-3661 ext. 110 or dharry@theforecaster.net. Follow him on Twitter: @DavidHarry8.