As luxury housing and shiny new offices went up near Stavis Seafoods’ home on the South Boston waterfront during the past decade or so, the fish processor and distributor continued to expand as well.

First, there was the addition to its Channel Street site. Then came the new corporate office at the Boston Fish Pier, and finally a plant near the Harpoon Brewery.

Now, a new stage has been reached: Stavis unveiled plans on Monday to put its 100 or so waterfront workers under one roof, as it becomes an anchor to a new development on Fid Kennedy Avenue, on a property in the city’s industrial park known as the Massport Marine Terminal.

The project represents an important milestone for the Massachusetts Port Authority, which has struggled to develop the approximately 30-acre property where Stavis will move. The site is specifically designated by the state for marine industrial uses, a designation that appeared to hamper past development efforts.

But Massport, with executives from Millennium Partners, decided to instead carve out a 6.8-acre parcel for the Stavis project, while freeing up the remaining 23 acres for other developers. The port authority, which controls the site through a long-term lease with the city, announced in early February that it would start seeking bids for that remaining space.

Stavis, in an announcement scheduled to coincide with this week’s Seafood Expo in Boston, said it will occupy up to 90,000 square feet in the $40 million project, starting in September 2018. The project will be developed by an affiliate of Millennium Partners, a firm better known in Boston for its high-rise housing in the city’s downtown.

“I would expect for us to grow as a result of this,’’ chief executive Richard Stavis said. “Ultimately, we’re doing this to grow and we’re doing it to reach a larger customer base.’’

Stavis said he expects construction will begin in September or October of this year. He said it is hard to know how many workers he’ll add to his team as a result of the move. One of the main goals, he said, is to modernize his processing operations to meet the requirements of the big distributors that buy his company’s seafood.

The Stavis relocation, which first became public in February, shows that some marine industrial uses are still thriving amid the rapid changes on the South Boston waterfront, also known as the Seaport District.

The property ended up in the spotlight last year when organizers behind Boston’s aborted bid for the 2024 Summer Games eyed the site as a home for the food wholesalers at Widett Circle, to make way for a stadium at Widett. The Olympics plans are dead, but city officials still want to redevelop Widett.

Mayor Martin J. Walsh and Massport chief executive Thomas Glynn issued statements praising the Stavis project. Walsh called it “a success story we should all be proud of’’ while Glynn said the development underscores “why port industrial land must be protected for the good paying blue-collar jobs that are supported by seafood processing.’’

Jon Chesto can be reached at jon.chesto@globe.com. Follow him on Twitter @jonchesto.