NYSE Liffe, the London-based derivatives exchange, today suffered an outage that knocked out trading in its bond, swaps and index products for over two hours and is the fourth systems glitch to hit the NYSE Euronext group in the space of two months.

The exchange operator confirmed that trading was halted in its number one "financials engine" - which covers all of its bond, swaps and index products -at around 15.10 BST. The exchange began what it termed the "pre-open" process at 15.50 BST. Trading resumed at 17.10 BST.