The US remains "obsessed" with the terrorist attacks on 9/11 and is unlikely to allow Arab investment into sensitive sectors such as airports and ports for years, says Prince Alwaleed bin Talal, the billionaire Saudi investor.

Concerns in Washington over national security last year forced Dubai Ports World to divest the US operations acquired as part of its takeover of UK ports operator P&O, raising fears of protectionism in Middle East investors.