The order has been placed with Hyundai Heavy Industries (HHI) in Korea, which is the largest in UASC's history, worth more than US$2 billion and includes all options.
The order features vessels that will be among the largest, most technologically advanced and environmentally friendly ever built.
UASC held a ceremony in Dubai where the newbuilding contract was signed by UASC chairman Salem Ali Al Zaabi and YJ Ji of HHI.
Said His Excellency Salem Ali Al Zaabi: "The exercising of these vessel purchase options is part of the newbuilding contract that UASC signed in August 2013. This vessel order positions UASC to deliver on its long-term growth objectives and the unique design features of the vessels that ensure UASC will set new industry benchmarks for fuel economy and environmental performance."
The 14,000-TEU and 18,0000-TEU newbuildings included in the overall order are scheduled for delivery from late 2014 and from the first half of 2015, according to Shipping Gazette.