Larry Ellison owns a fighter jet, yacht racing team and supercars galore, so what did the billionaire buy next? The Hawaiian island of Lanai

You probably would too if you had $36bn. Not content with a vast collection of toys that spans luxury homes, private jets, lavish cars and cup-winning sailboats, the software mogul Larry Ellison is splashing out on his own paradise island, it has been revealed.

The American founder of Oracle is buying Hawaii's sixth-largest island, Lanai, for a price estimated at around half a billion dollars – putting Britain's Richard Branson to shame, since his Caribbean idyll, Necker Island, is worth barely one-fifth of that.

What Mr Ellison gets for his money is 141 square miles of barely developed natural beauty, a property that has been called Pineapple Island because of its history of plantations growing the fruit.

These days it is a luxury resort, accessible to the billionaire set by helicopter or private jet. It boasts championship golf courses, opulent hotel resorts, and 47 miles of coastline that includes some of the most pristine beaches in the United States. There are barely 3,000 residents, few made-up roads and best of all, no traffic lights.

It is where Microsoft founder Bill Gates – one of only two Americans richer than Mr Ellison – married his wife Melinda, and he had been rumoured as a potential buyer himself when the island went up for sale at a price tag of between $500m and $600m. The previous owner, eccentric billionaire David Murdock, who masterminded Lanai's transformation from agricultural centre to a hang-out for the rich and famous,said Mr Ellison "will bring a new and fresh perspective to the island and its people," though the Oracle founder's plans remain a mystery. Mr Murdock is keeping a 2 per cent sliver of the island for himself.

"It is my understanding that Mr Ellison has had a long-standing interest in Lanai," Hawaii's governor, Neil Abercrombie, said, confirming the sale of the island after weeks of speculation. "His passion for nature, particularly the ocean, is well known specifically in the realm of America's Cup sailing."

For the four-times divorced Mr Ellison, Lanai is just the biggest and most expensive in a series of lavish purchases since he shot to the top echelon of the world's rich lists. Forbes, the business magazine which is the official arbiter of billionaire fortunes, ranks him as No 6 in the world, and Oracle – which he started as an experimental database software company in 1977 – now has its tentacles in almost every aspect of corporate IT.

Mr Ellison still runs it, and ranks as one of the best-paid chief executives in the US, too, but he has managed to combine that with pursuing the "passion for nature" that impressed the Hawaiian governor.

Ultra-competitive in sport as well as in business, he lavished an estimated $100m on his plan to win the America's Cup, which he duly did in 2010 with a 90ft trimaran called The BMW Oracle. His once-friendly and now bitter rivalry with biotech billionaire Ernesto Bertarelli, with whom he tussled in the courts over the rules to the America's Cup, has kept sailing journalists in copy for over a decade. Coming second, Mr Ellison always says, "just makes you first of the losers".

His collecting of billionaire toys seems compulsively competitive, too. At one point, he owned one of the world's largest luxury yachts, the 454ft Rising Son, only to sell it to record industry mogul David Geffen because he was frustrated it was too big to moor anywhere near shore. His garages are stuffed with sports cars, including a McLaren Formula One vehicle. And two years ago he rescued the US Open tennis tournament, and now owns a 50 per cent stake in the event.

Whatever his plans for Lanai, it doesn't seem likely that they involve simply sitting on the veranda and admiring the pineapples.