The Chicago Board of Trade, the second largest US derivatives market, has shrugged offer the latest price offensive in US treasury futures from arch rival Eurex US, but has refused to be drawn on whether it will retaliate.

Bernie Dan, president and chief executive of the Chicago Board of Trade said: "The CBOT is on track to post the best year in its history. We are experiencing record volume, including in our flagship US Treasury contracts, and our financial position is sound."