The Finnanger (Master Bernt Anton Thorbjørnsen) had been in convoy ONS-67, but lost contact after the heavy U-boat attacks on 24 February 1942 and was last seen by the Norwegian motor tanker Belinda two days later about 300 miles south of Cape Race.

At 02.34 hours on 1 March 1942, U-158 fired two torpedoes at an unescorted tanker, which had been chased since 21.00 hours the day before and missed. During a second attack run, the U-boat was apparently noticed because the tanker began to steam a zigzag course and the Germans had difficulties to get into a favorable attack position and eventually fired two stern torpedoes at 11.53 hours, both hitting the foreship of the tanker. At 12.15 hours, the U-boat began shelling the ship with the deck gun from a distance of 1000 metres, scoring two hits on the stern, but had then to break off the engagement due to return fire. The Germans re-opened fire from 4000 metres and scored hits on the stern and the bridge. After the crew abandoned ship, U-158 went closer and fired holes into the waterline with the deck gun and the 37mm AA gun until the ship capsized. They continued firing with the AA gun into the bottom until the tanker finally sank at 16.17 hours. The survivors were not questioned due to heavy seas and no radio messages were heard, but this must have been the Finnanger.