I've turned up two of these tools over the years, both stamped No. 989. However, I see from the web (below) that they also came in other numerical designations.
Given that there's no size stamped on the wrench, it's undoubtedly special purpose. "Svea" is a pretty common word in Swedish, since "Mother Svea" is the feminine personification of the country.
I think it's likely a jet wrench for a Svea camp stove. Carl Richard Nyberg founded the firm, initially making blow torches to his own design. His firm introduced the Svea 123 in 1959 and it went on to become one of the most popular backpacking white gas stoves ever made. In 1969, Optimus, another Swedish portable stove company, bought the company and continues to make this stove to this day.
Nyberg himself was a fascinating guy. He was an aviation pioneer and built a steam-powered flying machine, the Flugan (Fly). It's boiler was heated by four of his blow torches. Unfortunately, aside from a few short hops, it never really got off of the ground.