COPENHAGEN, Feb 24 (Reuters) - Denmark's A.P. Moller-Maersk said on Monday: * Maersk Drilling has taken delivery of its first ultra deepwater drillship, Maersk Viking, from the Samsung Heavy Industries (SHI) shipyard in Geoje-Si, South Korea. * Maersk Viking has started its voyage to the US Gulf of Mexico where it will commence a three year contract with ExxonMobil . * Maersk Viking is the first in a series of four ultra deepwater drillships to enter Maersk Drilling's fleet. The four drillships represent a total investment of USD 2.6bn and will be delivered from the SHI shipyard in 2014.