The board of the Chicago Board of Trade, the US futures market, met yesterday to discuss the rival bids of the Intercontinental Exchange and the Chicago Mercantile Exchange, amid speculation the CME may have to improve its bid to stay in the running for its Chicago neighbour.

Analysts estimate the ICE merger plan is now worth $2.2bn (€1.63bn) more to CBOT shareholders than the bid by their cross-town rival.