Ports companies have attracted many suitors in recent months

Goldman Sachs confirmed it was mulling over a possible bid with Borealis Infrastructure Management and Singapore firm GIC Special Investments.

But the BBC has learned that British investors are lining up a rival bid.

AB Ports operates from 21 sites in the UK and employs more than 3,000 people around the world.

The consortium's considerations are at a preliminary stage, and there can be no assurance that any offer will be made Goldman Sachs statement See AB Ports' share price

The rival British group, made up of investors and port operators, is believed to have been preparing its own offer for several months.

The Goldman Sachs-lead consortium could pay 740 pence a share, the City AM newspaper reports.

Its shares closed up 21 pence, or 3%, at 717p on Monday.

Speculation that it might be a takeover target began last week when the group's shares gained 10% in value.

Ports attract

Bidders have flocked to the UK's ports groups in recent months, attracted by rising world trade volumes as well as property assets.

OTHER PORTS BIDS DP Worlds bought P&O for �3.9bn in February following a bid battle with Singapore's PSA International Australia's Babcock & Brown bought UK ports operator PD Ports in January for �320m Europe's TUI bought container ships group CP Ships in December 2005 for �1.1bn The UK's Peel Ports bought Mersey Docks & Harbour for �771m in September 2005 Denmark's Meoller-Maersk bought Dutch rival P&O Nedlloyd in August 2005 for �1.7bn

Dubai Ports World recently spent $6.8bn to acquire P&O, while Mersey Docks and PD Ports were taken over last year.

AB Ports handles about a quarter of the UK's seaborne traffic, with sites at locations including Hull, Grimsby, Port Talbot and Southampton.

Additionally, it has a number of businesses offering specialist services and a US division, Amports.

"The consortium's considerations are at a preliminary stage, and there can be no assurance that any offer will be made," Goldman Sachs said in a statement.