Swansea Marine Panama S.A. was established in 1956. It was a type-C company mainly engaged in shipping and owner of the vessel "Olympic Breeze".
Sunstone Marine Panama S.A. was established in 1959. It was a type-C company mainly engaged in shipping and owner of the vessels "Federal" ("Adventurer" after 1963) and "Fort Bridger" ("Archer" after 1963). After 1975 Barillas Compania Naviera S.A. was the shareholder of the company. The company was dissolved in 1982.
Sunbeam Maritime Panama S.A. was a type C company, mainly engaged in real estate.
Sudbury S.A. was formed in 1981. It was a type -C company, owns a land at Glyfada.
State Mercantile Company S.A. was established in 1983. It was a type-C company mainly engaged in shipping as a vessel owning company. It belonged to United Investment Panama S.A. and after some years to Corvallis Navigation Panama S.A. and Edina Transportation Company (1983). The company owned the vessel "Olympic Dignity". This new company was formed after the division of the Onassis assets and the restructuring of the companies to serve the needs of the Christina Onassis group, which was managed separately by OMSA and separately from the Alexander S. Onassis Foundation's companies. The company was dissolved in 1983.
Springfield Shipping Company S.A. was established in 1963. It was a type-E company mainly acting as shipping agency. In 1990 belonged to Atol Group. Springfield Shipping Co. Panama S.A., was the technical manager of the tanker fleet and it's located in Palaio Phaleron. Its guiding principles are in the areas of crewing, safe and efficient vessels’ operations. After the transfer of OMSA's purchasing and technical departments from Monte Carlo to Piraeus it became integral part of Springfield" crewing agency company.
Southwind Maritime Panama S.A. was established in 1983. It was a type-F company and it is considered as dormant.
Southwest Consolidated Investments S.A. was established in 1983. It was a type-E company mainly acting as shipping agency. In1990 the company belonged to Atol Group.
Southport Maritime Corporation was formed in 1976. It was a type-C company, mainly engaged in shipping and acting as vessel owning company, as well as, touristic and shareholding company.It belonged to Oceanway Shipping Panama S.A. and owned the vessel Aristotle S. Onassis. This new company was formed after the division of the Onassis assets and the restructuring of the companies to serve the needs of the Christina Onassis group, which was managed separately by OMSA and separately from the Alexander S. Onassis Foundation's companies.