P&O Princess and Royal Caribbean are merging to form what they claim is the world's largest cruise line company.

The new company, as yet un-named, will operate 41 vessels, employing 40,000 people and will have a market value of about £4.2bn. Based in Miami, Florida, its shares will be dual-listed in the UK and USA.

Peter Ratcliffe, chief executive officer of P &O Princess Cruises said the cruise industry has sustainable long-term growth characteristics, despite the impact of recent events on short-term trading: The key indicators of demographics, penetration, high levels of customer satisfaction and trends in leisure spend point to significant growth over the long term and the increasing globalisation of the industry.

In a separate development, a shipping consortium is planning to build jet-powered ships capable of crossing the Atlantic in about three days.