Euronext made what has been described as a 'warm approach' to the London Stock Exchange about a potential deal in the spring of this year. The approach included the possibility of the two exchanges co-operating in the derivatives market and possibly even launching a joint bid for Liffe, the London futures and options market, which the French- led consortium last week bought for a handsome £550m (€886m).

Clara Furse, the LSE chief executive, decided not to pursue the offer of talks with Jean-François Théodore, chairman and chief executive of Euronext, and did not take the overture to the full board. She was already working on plans to buy Liffe, which she had been pursuing since she took up her new position at the beginning of the year. A source close to the London Stock Exchange source confirmed the Euronext approach last Friday: 'We are aware of warm overtures from Euronext at that time.'