HONG KONG - SWITZERLAND'S biggest bank UBS said on Wednesday it had sold about 3.4 billion shares in Bank of China through a placing to institutional investors.

In a statement released on Wednesday, UBS said the shares were acquired in 2005 in preparation for the Bank of China's US$11 billion (S$15.88 billion) initial public offering to the international market.

But the investment bank stressed it would maintain its close relationship with its Chinese counterpart.

'UBS remains committed to its business relationship with the Bank of China and to its businesses in China as a whole, where UBS will continue to develop its already strong client franchise,' the statement said.

Sources told Dow Jones Newswires that UBS sold the shares to 15 participants at a 12 per cent discount to Bank of China's Wednesday closing price, raising US$808 million.

The bank has lost billions of dollars in the United States subprime homeloan crisis and the ensuing financial turmoil. It has already written down about US$46.9 billion worth of assets. -- AFP