PORTLAND — Stinson Seafood Co. of Tenants Harbor said Wednesday it has purchased a Swedish-owned fish processing plant in Portland as part of a plan to bring to market a broad range of new products.

Abba North America, a subsidiary of Volvo Group of Sweden, sold its $20 million-a-year fresh-fish brokerage and filleting operation to Stinson on Monday for an undisclosed price.

All 25 employees of the Abba plant next to the Portland Fish Exchange have been offered jobs with the new company, said R. Woodman Harris, Stinson chairman. He said Stinson will add 10 to 15 new jobs at the plant by the end of the year and may eventually add a second shift to its only other fresh fish plant, in Rockland.

Stinson now employs 550 people at its six Maine canning, processing and buying facilities.

The company is developing new fresh and canned products such as herring burgers, herring nuggets, herring pops and cajun cod that includes spices, potatoes and other ingredients. The first of the new products, canned-smoked mussels, should be on the market by the new year, Harris said.

“There’s an awful lot of room in the seafood business for new products,” Harris said. “We want to go beyond a better sauce.”

The state-of-the-art production line at the four-year-old Portland plant will help Stinson produce the new products, Harris said.

The plant will provide a consolidated storage facility in Portland, a location that offers advantages in terms of both ease of transportation and access to the Portland Fish Exchange.