YANGON, March 11, 2008 (AFP) - Myanmar has launched a new gems auction hoping to sell off more than 100 million euros (153 million dollars) worth of precious stones, despite calls for a boycott, organisers said Tuesday March 11th.

More than 7,700 lots of gems, pearls and jade will be up for grabs at the 12-day sale which began Sunday March 9ht in the military-run nation, an official from the Myanmar Gems Enterprise told AFP.

"The 7,123 jade lots in this auction are worth about 78 million euros. This is the largest quantity of jade compared to previous auctions," said the official, who refused to be named as he was not authorised to speak to media.

Despite calls from the United States and human rights groups for a boycott of the sale after a crackdown on protests last year, organisers said they expect more than 3,000 foreign merchants from 20 countries to attend.

"China is the biggest customer for us, followed by Thailand," the official said, adding that the most expensive item was a 30-kilogram (66-pound) jade piece worth 2.38 million euros.

Myanmar has been hit by Western economic sanctions over its slow pace of democratic reform and the deadly crackdown on protests.

Gem sales bring in much-needed foreign currency, and the junta has been holding them with increasing frequency. The last auction was in January.

Myanmar, one of the world's poorest countries, is the source of up to 90 percent of the world's rubies, and each auction brings in more than 100 million dollars, making it a key source of revenue.

Buyers from China and Thailand have continued to attend the sales despite an international outcry over the suppression of pro-democracy protests in September, when the United Nations estimated at least 31 people were killed.

Following the crackdown, US First Lady Laura Bush and human rights groups urged companies to shun the auctions, while top jewellers Tiffany, Cartier and Bulgari said they would refuse to sell Myanmar gems.