The Monetary Authority of Singapore (MAS) said on Friday it is investigating allegations that financial institutions mis-sold risky derivatives linked to collapsed U.S. bank Lehman Brothers to retail investors.

About 9,700 people in Singapore, many of them retirees, stand to lose most or all of their money after they bought Lehman Brothers-linked structured products from banks and other financial institutions in Singapore.

These investors stand to lose over S$500 million in total, according to data provided by the MAS, which said it will make an announcement on action when its investigation is complete.

'MAS confirms that we have been conducting formal enquiries into allegations of breaches of the law, inadequate internal controls by the financial institutions or poor sales practices by their representatives,' its managing director Heng Swee Keat told a news conference.

MAS has said that while it can impose fines and suspend the licenses of financial institutions found to be in breach of its rules, it does not have the power to order banks to compensate investors.

Financial institutions that sold the Lehman-linked structured investments include DBS Group , Hong Leong Finance , UOB Kay Hian , OCBC Securities, a unit of the city-state's third largest bank Oversea-Chinese Banking Corp and ABN AMRO, now part of Royal Bank of Scotland.

'All the FIs (financial institutions) have also set up internal review panels which are checked by their CEOs,' Heng said.

MAS's move follows an deal reached in Hong Kong earlier on Friday whereby the territory's banks will buy back Lehman-linked structured products from holders at market value, as proposed by the government there.

Many Singapore and Hong Kong investors affected claim they were told the investments were relatively safe and that they had been asked to buy the products when they went to renew their fixed deposits. -- REUTERS