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

Speaking to journalists in New York last night, and reported by AFP, Mr Thain said he noted continued moves by Deutsche Börse to lure Euronext away from the agreed merger but said he would not increase his offer price, whatever plan the Frankfurt-based exchange came up with.

Deutsche Börse argued earlier this week that the terms of its proposal for Euronext were better than those of the NYSE, although the American exchange has guaranteed a cash portion of its offer.

Mr Thain's remarks came as Euronext - which operates the stock exchange of Amsterdam, Paris, Brussels and Lisbon - reported record revenues for the second quarter at €289.6 million.

Revenues from the cash trading of equities during the three months to the end of June leapt by 54.2 per cent to €77.07 million and revenues from derivatives trading rose 24.1 per cent to €107.2 million.

The exchange operator also said it was boosted by a jump in company listings.

Euronext, which claims to be the European leader for capital raisings over the three months to the end of June, made €14 million from company flotations during the second quarter, a 42.4 per cent increase over the same period last year.

Forty-one companies opted to join its market between April and June to take total listings over the first half to 62.

"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 [underlying] revenues," Euronext said.

"This strong performance has been achieved in spite of the impact of changes in the scope of consolidation," it said.

Euronext's chief executive Jean-Francois Theodore, and Mr Thain have said they are on course to complete their landmark merger during the first quarter next year.

At the beginning of June, the NYSE and Euronext unveiled an agreed £10.7 billion merger of equals that will create the world's biggest stock exchange.

Merging with Euronext will give the American exchange a firm foothold in the European securities markets, while its international counterpart will automatically leap into the US market.

Both exchanges had expressed an interest in buying the London Stock Exchange.

Euronext's Paris-traded shares rose to €68.75.

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