Nyse Euronext says the new fee system - known as Pack Epsilon - will be effective from 1st July 2008 for all stocks listed on Euronext Amsterdam, Brussels, Lisbon and Paris "to address the growing demand of high frequency trading". Under the new pricing structure, high-frequency trading clients will be charged for the first partial order execution only, rather than being charged for each partial execution linked to the same order. This will "allow eligible clients to increase their order flow in Euronext stocks", says the exchange.