Stena Line is introducing a new service from Poland with an Ernst Russ ro-ro.
The 1,625-lane-metre Elisabeth Russ (built 1999) will operate six times a week between Gdynia and Nynashamn in Sweden from 16 October.
"The demand for freight capacity in the Baltic Sea has been growing steadily over the last number of years and Stena Line is supporting this growth through investing in a new route," it said.
CEO Niclas Martensson added: “This is another important step where we are seeing a strong demand from our customers and also where we are building for the future.
"We will continue to develop our business in line with customer and market demands and the new route will be an important complement to our existing Baltic Sea routes.”
Stena Line has been operating from Gdynia to Karlskrona in Sweden for more than 20 years.
The freight-only vessel will carry a mix of trucks with drivers, trailers and containers.
The trip takes 18 hours.