1976 - United Thai Shipping Corp Ltd (UTSC) established to serve the government's vision in founding a "Thai national flag carrier" and started Europe/S.E.Asia/USA conventional liner shipping services.
1987 - Unithai line Plc Ltd established and subsequently expanded the services South and West Africa, the Middle East and North Asia.
1990 - Unithai Shipyard and Engineering Ltd (UTSE) established at the Laem Chabang Deep Sea Port.
1994 - Unithai forms joint ventures with Sojitz Logistics Corp and Maruzen Showa Unyu Co Ltd to establish United Thai Logistics Co Ltd (UTLC) and United Thai Warehouse Co Ltd (UTWC).
1995 - Unithai Container Terminal (UTCT) established in Samut Prakhan province and commences operations in 1997.
1999 - Joined forces with SDV France to establish SDV Logistics (Thailand) Co Ltd to provide International Freight Forwarding Service.
- Uniwise Offshore Ltd created by joint venture with Cuig Maritime, Singapore to provide crew-boat services to the oil and gas industry in Thailand. This JV subsequently expanded to provide all type of offshore supply vessels and establishment of Uniwise Towage Ltd.
2000 - Unithai's Offshore Division, through CUEL, established to provide a complete range of services for offshore facilities.
- UTSC owns and operates VLCC MV. Thai Resources.
2001 - Unithai forms joint venture with Norway’s ‘Gearbulk’ named ‘UniGear’ to operate a south African service.
2002 - UTSC commences dry cargo transportation service (Panamax size bulkers).
2005 - Unigreen Agencies established to represent the general agents in Thailand of one of Korea's largest shipping lines – STX Pan Ocean Co Ltd.
2008 - Unithai formed a joint venture with Maruzen Showa Unyu, Tan Cang – Song Than ICD Ltd, Transport and Chartering Corporation and Viet Business to establish Unithai Logistics (Vietnam) Corp (UTLV), in Ho Chi Minh City.
2014 - Unithai forms joint venture with Chin Corp Myanmar to establish Unithai Chin Corp Logistics (Myanmar) Ltd (UNICHIN).