The move follows the offer made by Spanish construction firm Grupo Dragados in February to take over all of HBG and the subsequent sale of a 23% stake in Grupo Dragados to yet another Spanish construction firm, ACS.

Ballast Nedam cannot be convinced that Ballast HAM Dredging will remain independent following these unforseen changes and is thus seeking to exercise the clause which entitles it to the HBG stake in the joint venture.

HBG has predictably refused to transfer its interest and the matter looks set for arbitration through the Dutch courts.

This is the latest chapter in a long-running story which saw the formation of Ballast HAM Dredging late last year save HAM Dredging from the predatory advances of industry giant Royal Boskalis Westminster despite the opposition of HAM parent company HBG's shareholders, which had led to lengthy court battles.