The Greenbrier Cos. said Tuesday it sold its Gunderson Marine barge building operation to a newly formed company that plans to expand production on the Portland waterfront.

Greenbrier, which had already announced plans to stop making railcars at the Northwest Portland riverfront site and lay off 101 this year, said Tuesday’s deal preserves 300 jobs from the barge manufacturing business. The new owners say they hope to boost Gunderson’s workforce.

“The facility has a tremendous amount of room to accommodate other fabrication,” said Marvin “Dee” Burch, co-founder of Oregon Green Manufacturing, the new company created to buy the Gunderson site.

Burch is president of Advanced American Construction, a marine construction business also based in Northwest Portland. He formed Oregon Green Manufacturing with Terry Aarnio, who owned Oregon Iron Works until its sale to Vigor Industrial in 2014.

The companies didn’t disclose terms of their deal, which closed Monday, but said there were no public incentives associated with the transaction. Workers at the Gunderson site are not unionized.

Gunderson emerged from a steel fabrication business two brothers started in Portland in 1919. It has been building ships since 1941, operating on the Front Avenue site beginning in 1947. Greenbrier acquired the company in 1985.

The 58-acre site on Front Avenue will retain the Gunderson Marine name, Burch said, with Oregon Green Manufacturing serving as its parent company.

The Gunderson property once had 1,800 people working along the Willamette River, according to Burch. He said he and Aarnio will use their experience in metal fabrication and marine construction to explore other opportunities for the property including electric tugboats, wind energy platforms, wave buoys, bridge girders and components for river dams.

“We’re really looking at as many areas as we can to get that space operating again,” Burch said.

Greenbrier announced last fall that it would shut down the Gunderson railcar factory in Portland, shifting production to factories elsewhere in the country that are closer to its customers and other railcar operations. That left the site of the adjacent barge operation uncertain, along with the 300 factory jobs.

“The transition of Gunderson Marine and the Front Avenue site leaves us encouraged but also with a heavy heart,” Greenbrier CEO Lorie Tekorius said in a written statement. “We have been a steward of the Gunderson location since entering railcar manufacturing in 1985. The facility holds a special place in the life of Portland and Oregon.”

Greenbrier’s headquarters remain in Lake Oswego, where it employs more than 250, including about 70 that recently relocated from the Gunderson site who work in engineering, information technology and other corporate functions. Greenbrier continues to build and manage railcars at sites around the country, businesses it runs from Lake Oswego.

“We’re going to maintain a significant presence in Oregon,” Greenbrier Vice President Jack Isselmann said Tuesday.