John Thain, CEO of the New York Stock Exchange, has said he will not improve terms of its £10.7 billion merger with Euronext, despite noises from rival Deutsche Borse that its proposal was worth more.

The Times (London) reports: “Speaking to journalists in New York last night, and reported by AFP, Mr Thain said he noted continued moves by Deutsche Borse to lure Euronext away from the agreed merger but said he would not increase his offer price, whatever plan the German exchange came up with.”

Euronext said: “This first half of the year has been the best one ever for cash and derivatives markets and has created the conditions for all business lines to register an increase in their revenues. This strong performance has been achieved in spite of the impact of changes in the scope of consolidation.”

Euronext’s Chief Executive, Jean-Francois Theodore, and John Thain have said they are on course to complete their landmark merger during the first quarter of next year.