GENEVA (AP) _ Much of his long life overflowed with color and controversy. But his death was shrouded in mystery and silence.

Stavros Niarchos, the 86-year-old billionaire shipping magnate whose death was announced Wednesday, chose to be buried in a simple cemetery in Switzerland, perplexingly far from his Greek roots.

And with the family imposing a strict news blackout, the future of the tycoon's fortune _ estimated at about $4 million _ was uncertain. Would the vast estate _ which reportedly ranged from racehorses to priceless works of art _ be split between his three sons and two daughters?

``No one is allowed to reveal any information,'' said an anonymous spokesman for his London-based company, Niarchos Ltd. The statement was echoed by officials in Greece and Switzerland.

The secrecy surrounding his death is in marked contrast to the gossip and headlines Niarchos inspired in his heyday.

Dubbed the last of the `Golden Greeks' of the shipping world, he was notorious for his passion for business and women and for his rivalry over both with another shipping legend, Aristotle Onassis.

His famous yacht _ the 375-foot Atlantis _ was designed to be 50 feet longer than Onassis' cruiser. And the rivalry extended to their private Greek islands, with Onassis buying Skorpios a few years after Niarchos bought his.

Niarchos was married six times _ twice to the same woman. The jet set was shaken to the core by allegations that he was implicated in the 1970 death of his third wife. Her body was found on the family's island, filled with an overdose of barbiturates and covered with suspicious bruises.

One year later, Niarchos married his deceased wife's sister, Tina, the former wife of Onassis, in what many said was an attempt to get even with his rival.

Tina's sudden death in 1974, also under mysterious circumstances, marked the start of Niarchos' retreat into reclusion. But even in hiding, he retained his taste for luxury.

In addition to his private Aegean island, Niarchos kept residences in Paris, London, New York and the exclusive Swiss resort St. Moritz, where he loved to ski.

He was considered a major art collector and owned priceless works by El Greco, Gauguin, Renoir, Cezanne and Van Gogh, which he displayed at his homes and aboard his yacht. He was also one of the world's leading private collectors of ancient Greek art.

While other members of the jet set gladly posed for photographs on the slopes and at celebrity events, Niarchos shied away from the glare of publicity.

Locals in St. Moritz said Niarchos kept himself to himself whenever he stayed in his vacation villa on the outskirts of the town.

Comforted by the famous discretion of the Swiss, Niarchos also spent much time in the Swiss financial capital, Zurich.

There was speculation _ but no confirmation _ that he chose to live his final days in Switzerland because of the relatively favorable treatment on inheritance tax.

Niarchos died quietly in a Zurich hospital on Monday. No cause of death was given, although he had reportedly been on life support for weeks after suffering a stroke. After a flurry of rumors, Niarchos Ltd. in London reluctantly confirmed his death Wednesday.

Swiss authorities tried to stay tight-lipped about funeral plans, at the family's request. But officials in Lausanne, who asked not to be named, eventually confirmed that the billionaire would be buried in strict privacy Thursday after a service in the city's Greek Orthodox church.

No one could say why Niarchos would be buried in a simple, state-owned cemetery, near the town's main highway.

And no one was willing to comment on why the tycoon had chosen Lausanne _ where he had no apparent connection _ rather than his Greek birthplace or one of his many homes.