Chi-X, an equity trading system that claims to be quicker and cheaper than Europe's largest stock exchanges, has started trading the most liquid UK equities in a move that brings it head-to-head with the London Stock Exchange.

Chi-X, the European blue-chip share trading system from Instinet, has started offering its broking customers the ability to trade the UK stocks that make up the FTSE 100, the index of top listed companies. It launched to take advantage of European Commission rule changes to increase competition between exchanges and alternative trading systems.