HAMILTON, BERMUDA--(Marketwire - Jun 28, 2012) - North Atlantic Drilling has received a letter of intent from ExxonMobil for assignment of the harsh environment semi- submersible drilling unit West Alpha. The extension has a firm period of two years with an estimated revenue value of US$410 million. Commencement of operations under the contract extension is expected in the third quarter of 2014, in direct continuation of the next assignment for West Alpha on the Balder field. Consequently, West Alpha has secured firm contracts that will keep the rig employed to third quarter 2016.

The customer has an option to extend the contract with one additional year at the same terms as for the first two years.

Seadrill has a 74% ownership interest in North Atlantic Drilling Ltd.

This information is subject of the disclosure requirements pursuant to section 5-12 of the Norwegian Securities Trading Act.

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Source: Seadrill Limited via Thomson Reuters ONE [HUG#1622622]