Osborne Panama S.A. was formed in 1965. It was a type-C company mainly engaged in shipping.
Onaway Transportation Company was formed in 1973. It was a type-C company acting as passive company.
Omiros Maritima S.A. was formed in 1955. It was a type-C company mainly engaged in shipping.
Olympic Whaling Company S.A. was formed in 1950. It was a type-C company. It was also the owner of the tanker Olympic Challenger and along with Balleneros Limited S.A. the owner of Onassis whaling fleet.
Olympic Transportation Company was formed in 1952. It was a type-C company mainly engaged in shipping and owner of the vessel Olympic Mountain.
This is an intermediate aunt company type-D, called Olympic Oil Lines, Panama SA, which was the temporary owner of ships. For example it was this company that ordered the construction of the Olympic Flame at the Bethlehem Shipyards in the USA in 1949. After the loan was repaid another C company was formed, in this case Seaford Marine S.A., to own the vessel. This aunt company belonged to the mother company Aristomenis, which was owned by the grandmother company Miraflores.
Olympic Maritime SA (OMSA for short), which was founded in Paris 1952 and the headquarters of which moved to Monte Carlo in 1954, was Onassis’s main shipping agency. Olympic Maritime remained in Paris as the branch office of OMSA in Monte Carlo, while another OMSA branch office was founded in London. Olympic Maritime SA and its branch offices were the main agencies of the group. Each daughter/mother/grandmother company gave OMSA the jurisdiction to manage each ship (and any other assets) with a decision of the Board of Directors. In 1990 OMSA passed to the Athena Onassis Group of Companies with A company Atol Compania Naviera S.A. and B company Redonda Navigation Panama S.A.
Since 1990 the main management company of the Business Group of the Alexander S. Onassis Foundation is Olympic Shipping and Management S.A.; The company was dissolved in 2012.
Olympic Investment Inc. was formed in 1993. It was a type-F company considered as dormant.
Olympic Finance Inc. was formed in 1993.
Olympic Airways S.A. was formed in 1957. It was an aviation company. In 1971 Olympic Airways set up a subsidiary company for light aircraft and helicopters called Olympic Aviation Inc.
Olinda Panama S.A. was formed in 1966. It was a type-C company mainly engaged in shipping and owner of the vessel Olympic Prestige. The company was dissolved in 1993.
Oceanway Shipping Panama S.A. was formed in 1976. It was a type-C company mainly acting as intermediate holding company and engaged in shipping as vessel owning company. The company belonged to Southport Maritime Corporation (1977) and after some years to Dorset Shipping and Trading Corporation (1986). It owned the vessel Universe Frontier. 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 2000.
The Oceanic Transport Corporation was formed in 1949. It is a type-C company engaged mainly in shipping. From 1950 it owned two vessels, General Artigas and General Rivera.
Occidental Shipping Company S.A. was formed in 1956. It was a type-C company mainly engaged in shipping and owner of the vessel Olympic Falcon. Since 1983 it was a dormant company.
Occidental Carriers S.A. was formed in 1983. It was a type-C company mainly engaged in shipping as the owner of the vessel Olympic Melody.
Obelisk Navigation S.A. was formed in 1986. It was a type-C company mainly engaged in shipping as the owner of the vessel Olympic Loyalty.