Associated British Ports, the owner of 21 ports including Southampton, is to be taken over in a £2.5bn deal.
ABP has accepted an offer of 810 pence per share from a consortium which includes Goldman Sachs for a portfolio of ports that handles about a quarter of the UK's seaborne traffic.
There have been a series of takeovers of British port owners in recent times, in anticipation of a rapid increase in trade volumes. P&O, Mersey Docks and PD Ports have also changed hands in the last 12 months.
The spectacular growth of the Chinese and Indian economies has fuelled interest in infrastructure and cargo handling assets.
ABP employs 3,000 staff worldwide, including in the US where its Amports business handles vehicle imports and exports.
"ABP is a unique strategic asset," said AB Ports chairman Chris Clark.
"The consortium's offer reflects that and recognises the strong operational and financial performance of the business."
