The golden days of the great Greek tanker owners, men like Aristotle Onassis and Stavros Niarchos, may be over. But now a new shipping tycoon has taken charge on the high seas.

Norwegian John Fredriksen, who began his career as a messenger boy at a shipping company in Oslo, can claim the throne as the world's richest shipowner. Fredriksen underlined his authority this week when his World Shipholding Group doubled its stake in Singapore's Osprey Maritime.

The deal adds another six huge vessels to a portfolio that numbers more than 60, half of those the supertankers, very-large-crude-carriers, that dominate world oil trade - a multi-billion dollar fleet.

The Osprey takeover also lands Fredriksen six highly-prized liquefied natural gas carriers, in demand to meet growing world gas trade. It was the latest in a number of tempestuous takeover battles which has seen the Norwegian magnate hand heavy defeats to Swedish and Greek competitors.

Fredriksen dominates his industry during a boom year for oil shippers with charter rates paid by the petroleum companies to ship crude around the globe up fourfold since January. Freight rates for a supertanker sailing from Saudi Arabia to Japan have risen to $5.5 million for a single voyage.

Fredriksen established himself on the secretive shipping scene during the 1960s and 1970s in Singapore and New York. Never averse to risk, he made his name during the "tanker war" of the 1980s in the Iran-Iraq conflict.

His fleet risked Iraqi missiles to load at Iran's Kharg Island terminal and Fredriksen made a fortune. His tankers also were alleged to have taken the risk of burning their customers' cargoes for fuel. Fredriksen spent time in custody during the investigation.

His Sea Empress went down on the rocks off Milford Haven, on Britain's west coast, in 1996 but fortunately for Fredriksen the environmental damage was minimal.

Fredriksen's big takeover victory came during the late 1990s downturn in tanker rates that coincided with the slump in oil prices. His hostile bid for Swedish tanker operator ICB took two years to complete and on closing it Fredriksen appointed ICB's president Ola Lorentzen as his Managing Director, a move applauded by the industry.

Having faced Fredriksen from the other side of the negotiating table, Lorentzen describes him as a "determined man". "That's a positive description, don't you think?" he asks, "After all, it's all

In March 2000 Fredriksen pounced on the debt-laden U.S. group Golden Ocean, at the time the world's largest tanker fleet. His Norwegian company Frontline fought off Greek shipping families Kollakis and Restsis to take over the brand new $1.2 billion fleet.

Fredriksen also holds a third share in his home town Valerenga football club - one of his few enterprises that doesn't make much of a profit. "The football thing was purely done for nostalgic reasons, it wasn't a money-making deal," said a close friend. "The team is from where he grew up.

He doesn't get half as excited as the rest of us. He doesn't find much time to watch." Despite the hard nose for business, Fredriksen is described as a retiring man, heading off at any opportunity to go fly-fishing. He has yet to give an interview to the media.