By Stephanie Nebehay
GENEVA, Nov 19 (Reuters) - Nearly 150 jewels including the star lot, a huge blue diamond, were left unsold at Sotheby's on Wednesday night, as jittery buyers held back amid uncertainty in world markets, the auction house said.
Only 60.6 percent of 371 lots on the block found new owners, after another 30 gems were withdrawn ahead of the Geneva sale.
The world's largest publicly traded auction house said it netted 17.9 million Swiss francs ($14.85 million) compared with 60 million francs at its jewellery sale last May in the city.
"I think had we been having this sale six months ago, it would have been a very different story," David Bennett, Sotheby's jewellery chairman for Europe and the Middle East, told Reuters after conducting the auction.
"Clearly the market is in transition and like all markets in transition, people stand back to see what is going to happen," he added. "People aren't flooding into the stock market because they can't see a pattern. I think it was the same thing here."
Turnover levels had returned to those of May 2005, according to the British auctioneer. He expected it would be "at least the end of the year before we can see where the market is headed".
The blue diamond, which weighs 10.48 carats, went unsold after bidding peaked at 5.7 million francs -- short of the secret reserve price set by the unidentified seller. Sotheby's had estimated it could fetch up to 10 million francs.
The Lesotho I, a 71.73 carat light brown diamond mounted on a ring by U.S. jewellery Harry Winston, also went unsold.
"It has to wait for another year," Bennett told the crowd after the huge and historic stone, which had been forecast to fetch 3.3 million-5.6 million francs, stalled at 2.5 million.
A pink diamond ring of 8.02 carats was bought for nearly 1.60 million Swiss francs ($1.33 million) by a man in the room. It was the evening's best result.
A pearl necklace with a clasp set with a large emerald surrounded by diamonds fetched the same sum, which includes the premium paid by the buyer in addition to the hammer price.
A stunning necklace with nine rows of natural pearls soared to 1.14 million francs, going to another bidder in the room.
A round 11.70 carat Golconda diamond, set in a ring by the American Paris-based jeweller known as JAR (Joel Arthur Rosenthal), sold for 1.2 million francs to a London-based dealer who said it was for a client in the Middle East.
"The Golconda did very well, it is a splendid stone, and natural pearls also did very well. Overall, the general pattern is fine things are selling very well indeed," Bennett said.
Andy Cohen, a Geneva-based trader, said: "Certainly prices are lower, except for natural pearls. There is a flight of cash towards what is truly rare.
"The world is a different place today than when the reserve prices were set," he added. (Editing by Andrew Roche)