 Aker Barents subsequently commenced drilling operations on the Norwegian continental shelf for Det Norske Oljeselskap ASA (earlier Aker Exploration ASA) in July 2009.And in 2010, Aker Spitsbergen commenced drilling operations for Statoil ASA.In February 2011, Aker drilling was relisted in the Oslo stock exchange under the ticker - 'AKD', three years after being taken off the exchange.