The trade body for global derivatives dealers has added to the ongoing debate over market legislation being drawn up by the European Commission, with two letters that raise concerns over the implementation of rules that will affect the trading of derivatives.

The International Swaps and Derivatives Association sent the letters to Patrick Pearson, head of the financial market infrastructure unit at the EC, on July 30. Isda urged the EC and the European Securities and Markets Authority, the region's top financial regulator, to provide greater clarity on how new rules will apply to firms that clear derivative trades through clearing houses situated outside EU.