John Fredriksen and family

John Fredriksen and family

Rank: 7 Worth: £6,200m

John Fredriksen is a Norwegian-born Cypriot oil tanker and shipping tycoon, owner of the world's largest oil tanker fleet, and was Norway's richest man until he chose to abandon his Norwegian citizenship and take up a Cypriot passport after the Norwegian government tightened the tax regime. Norwegian magazine Kapital listed Fredriksen in 2010 with a net worth of NOK 69 billion ($13 billion USD). Through his investment companies Hemen Holdings and Meisha, Fredriksen controls the companies Frontline and Golar LNG from London.

He also has major interests in the offshore driller SeaDrill, the fish farming company Marine Harvest the dry bulk company Golden Ocean Group, and supply vessel company Deep Sea Supply. Fredriksen also recently announced that Frontline through acquisitions and options and secured 9,6% of the worlds largest shipholding company Overseas Shipholding Group.

He is now the world's largest tanker owner, with more than seventy oil tankers, and major interests in oil rigs and fish farming. His fleet is dominated by costly double-hulled, environmentally safer tankers.

He built the bedrock of his fortune in the Iran-Iraq war of the 1980s when his tankers braved the fighting to pick up oil at huge profit. In 1996 he acquired control of the Frontline shipping operation. His stakes in it and five other companies quoted on the Oslo, German or New York exchanges are worth £5 billion.

A Family Affair

Some of Fredriksen company boards include his 27-year-old twin daughters, Kathrine and Cecilie.

Cecilie graduated from London Metropolitan University and her directorships include Frontline, the Fredriksen company said to be the world's biggest tanker operator. She also sits on the board of Seawell, which took control of an American oil services firm in a £500m deal last year. The CV of Kathrine, who attended the European Business School in London, includes Arcadia Petroleum.

But it's not all work and no play for the sisters. Kathrine was reported to be using crutches decorated with Swarovski crystals after breaking her leg in a fall. The heiresses and their 66-year-old father spend much of their time in London.

He is a generous donor to medical research. The Inger and John Fredriksen Ovarian Cancer Research Foundation commemorates his wife, who died in 2006.