Just days after ABP’s board accepted a revised £2.48bn (810p per share) offer from Admiral Acquisitions UK Ltd, the Macquarie Consortium entered the fray promising at least 840p per share (£2.57bn).

Admiral showed its determination to secure ABP by upping its bid to £2.57bn to head off Macquarie.

Earlier ABP chairman Chris Clark had described ABP as a “unique asset”, with Admiral’s 810p a share offer an “excellent opportunity for shareholders to realise the significant value that has been created”.

Now, the ABP board says it will evaluate the Macquarie Consortium’s offer in light of the revised cash bid from Admiral.

Admiral has been formed by investors Goldman Sachs, Canada-based Borealis Infrastructure Management and the Government of Singapore Investment Corporation.

Macquarie involves Macquarie European Infrastructure Fund, Macquarie European Infrastructure Fund II, 3i Group plc, Canada Pension Plan Investment Board, Industry Funds Management and Macquarie Bank Ltd.

ABP shareholders will still need to approve any takeover.

ABP owns 21 UK ports and handles about 25% of British seaborne trade, including timber imports to ports such as Newport and Hull.