The bid is the third offer made by the consortium, called Admiral Acquisitions UK Ltd, for Britain’s biggest ports operator which controls 21 UK ports.

It is designed to head off a challenge from the Macquarie consortium, which had promised at least £2.57bn (840p per share) for ABP. Macquarie is now considering its response.

The ABP board had already accepted an earlier bid by Admiral but also opened its books to the Macquarie consortium, when the latter declared its interest.

ABP handles about 25% of British seaborne trade, inclduing timber ports such as Newport and Hull.