Way clear for German move for US exchange

The pair concluded that the proposed takeover would not be approved by American regulators. NYSE Euronext had already rejected the unsolicited approach last month.

The NYSE-Deutsche Boerse tie-up, worth some $10.2bn, is also subject to regulatory scrutiny in Europe and the United States.

Yesterday's developments across the Atlantic came as the London Stock Exchange (LSE) vowed to press ahead with a merger with its Toronto counterpart, despite the emergence of a rival Canadian bidder.

Over the weekend, Maple Group, which is made up of Canadian pension funds and banks, tabled a 1.8bn bid proposal for the Toronto exchange (TMX) designed to keep the bourse in Canadian hands.

The LSE unveiled its own merger proposal with TMX in February as part of chief executive Xavier Rolet's desire to play a central role in the consolidation of international stock exchanges.

In a statement yesterday, it said it remained committed to the deal: "The proposed merger offers compelling financial, strategic and operational benefits for shareholders, the full breadth of market participants, listed companies of all sizes, investors and other stakeholders."

TMX has said it will assess the higher offer from Maple but that in the meantime it continued to back its existing merger partner.

Analysts have warned that the LSE could find itself vulnerable to a bid if its planned tie-up falls through. IG Index sales trader Will Hedden said: "It potentially makes the LSE a takeover target if its own bid is scuppered."

If successful, Deutsche Boerse's deal with NYSE Euronext will see the German operator emerge as a global powerhouse and force rivals to scale up in order to stay in competition.

"LSE will look towards Nasdaq if it does not get a deal with TMX. Nasdaq does not bring derivatives, but it is a more attractive option (for LSE] than ICE," one banker said.