John Thain, chief executive of the New York Stock Exchange, said he expects a merger with Euronext to close by the end of March shortly after a pact of five banks with about 10% of Euronext dissolved amid signs of fragmenting views ahead of Tuesday's vote on the proposed $28bn (€21bn) tie-up.

Thain told a conference in the US: "We still need a final sign-off from the regulators and we anticipate closing toward the end of the first quarter."