For nearly a decade, a massive plant in Elma that Western Electric had started in the 1970s but never finished sat idle on Maple Road.

Along came Steuben Foods, which was in the market for more space. In 1983, the food manufacturing and packaging company agreed to a lease with the Erie County Industrial Development Agency, which by then was the property’s owner.

Over the past 26 years, Steuben has invested more than $200 million in the complex, has paid the ECIDA $6.8 million in rent, and today fills about half of the total space.

Now Steuben has shifted from tenant to owner. The company on Wednesday marked its acquisition of the 150-acre property from the ECIDA, describing plans to eventually use all of the plant’s space and hire more workers.

Since starting yogurt production at the site in 1985 with 125 employees, Steuben’s workforce has nearly quadrupled to 475 people.

The company develops and makes dairy, soy-based and nutritional beverages, as well as broths and puddings. They are sold under brand names of major food companies, restaurants and food retailers, as well as its own Whitney label.

The Elma site in the 1970s was envisioned as a new home for Western Electric, which intended to move its operations there from the Town of Tonawanda.

But after erecting the 786,000-square-foot shell off Route 400, Western Electric abandoned the project. Michael Nolan, now the town supervisor, recalled it as a place to ride snowmobiles through as a youngster.

“Back in the 1970s, this property was a very sore subject in the Town of Elma,” Nolan said.

The ECIDA became the property’s owner in 1980, marking the agency’s first redevelopment project. When Steuben was exploring sites for an expansion, it considered the unfinished Elma plant, but the site was not on its short list, said Kenneth Schlossberg, Steuben’s president. The plant lacked access roads and utilities.

The ECIDA and its partners stepped in, assembling an initial $6.2 million incentive package to make site improvements that helped win over Steuben, which invested $16 million in the project.

The company was allocated 5 megawatts of low-cost power from the New York Power Authority, a figure that has since grown to 8.75 megawatts. Schlossberg said the low-cost power allocation was vital to Steuben’s decision to choose Elma.

“Without their hydropower, we would not be here today,” he said.

Nolan said it will be crucial to Steuben’s local presence to renew the company’s contract for low-cost power.

“This isn’t a what, if, or a maybe,” Nolan said. “We’ve got a success story with 475 jobs.”