The Deutsche Boerse bid is backed by leading European politicians

Euronext bosses agreed a rival $10bn (8bn euros; �5.5bn) tie-up with the New York Stock Exchange earlier this month.

Deutsche Boerse is expected to seek support for its offer from Euronext shareholders and European politicians.

Its concessions offer Paris-based Euronext more power within any merged organisation.

No extra cash

Some analysts had expected Deutsche Boerse to improve the financial terms of its offer, perhaps by raising the cash component of the bid.

Instead, on Monday the operator of the Frankfurt stock exchange said that the headquarters of any new company would not have to be in Frankfurt.

It said that the control of group functions would be split between Frankfurt and Euronext's sites in Amsterdam and Paris.

It also agreed to retain more of Euronext's trading platforms.

French President Jacques Chirac, Italian Prime Minister Romano Prodi and European Central Bank boss Jean-Claude Trichet have all said that they favour a Euronext-Deutsche Boerse merger ahead of a trans-Atlantic deal.

New York Stock Exchange chief executive John Thain said there was nothing "substantially new" in Deutsche Boerse's concessions.

"Based upon what I have seen so far, I don't see any reason to change any element of our transaction," he said.

Mr Thain has suggested that a merger between the New York Stock Exchange and Euronext could lead to a new London market being opened to rival the London Stock Exchange.