Lossie was ordered by the United States Navy as PG-103 and was built to the RN's specifications as a Group II River-class frigate.

She was transferred on 12 August 1943 while still under construction from the USN to the RN under the auspices of the lend-lease program.

Lossie picked up 112 crew from the Nellore the following week near the Chagos Archipelago and landed them at Addu Atoll.

Lossie was decommissioned and stricken from the RN on 26 January 1946 and was returned to the USN at Boston, Massachusetts two days later as PG-103.

The USN sold her on 13 November 1946 to Cadio Compania de Navegacio S.A. of Panama and she was registered as Teti.