HELLENIC EXCHANGES S.A.: Margin Parameter Change

As of Tuesday 24/03/2009 the fixed volatility parameter that RIVA uses for the margin calculation for the derivative products on the indices FTSE/ASE-20 and FTSE/ASE Mid-40 is being adjusted from 50% to 44%.

This change will come into effect for the open positions that will arise at the end of the trading session of 24/03/2009.