The acquisition of the provider of subsea consultancy and project engineering services also includes a three-year earn-out period based on EBIT performance.

Neptune chief executive Christian Lange said the acquisition of SES would expand the group's subsea capabilities and build on the successful integration of Neptune Ross Deeptech to provide significant growth opportunities in the North Sea region.

"The addition of SES will provide Neptune with greater market presence and the opportunity to capitalise on the $40-plus billion in subsea expenditure that is forecast for the European market over the next four years," he added.

He also said SES will provide Neptune with the capability to design specialist subsea equipment, further enhancing its global service offering.

The acquisition is subject to Neptune obtaining finance.