A row about the future of the over-the-counter derivatives market has emerged as a trade body for OTC brokers slammed a US plan to force products on to exchanges, while NYSE Euronext, the largest US stock exchange, backed the controversial proposal.

The Wholesale Markets Brokers' Association, which represents the largest OTC brokers, said the plan outlined yesterday by US Treasury Secretary Tim Geithner to force OTC products on to exchanges "would significantly reduce liquidity in financial markets, resulting in increased risks and costs for end users".