OMX has announced plans to apply post-trading anonymity to a third of its cash equity market in Iceland, Helsinki and Stockholm, in a bid to drive down costs and to compete with anonymous off-exchange systems.

Under the system which goes into effect May 2008, only the parties involved in the trade know its respective counterpart. It will apply to OMX's five most traded stocks, which are currently Ericsson B, Volvo B, TeliaSonera, Nordea and H&M B. The five represent 33% of the total turnover in Stockholm, based on individual shares between January to September this year, according to OMX.