LSE in merger talks with Singapore exchange It is not clear how the merger would be structured, but due to SGX's larger market capitalisation - £4.4bn against LSE Group's £2.8bn - it is thought a takeover of its British rival is the most likely option. However, it is known Mr Rolet is likely to want a strong voice in any enlarged group, and is likely to be arguing for a large portion of the combined business to remain domiciled in London. While banking sources indicated that any form of formal offer is still some time away, market rumours suggested a takeover would be in the region of £13.50 per LSE Group share. Last night the British bourse's share price closed up 21p at £10.23, with the price spiking in late-trading amid merger speculation. The talks between the two exchanges are understood to have been sparked by an initial conversation about launching a so-called 'international board," allowing trading of the LSE's largest companies on the Singapore bourse, and vice-versa. That deal was announced last week. If the exchanges merger is confirmed, LSE Group, chaired by Chris Gibson-Smith, would require the support of its two largest shareholders - Qatar Investment Authority and Borse Dubai - who together own 35.6pc. But, even with shareholder support, the transaction would still require regulatory approval from the European Union and Singapore authorities. Both the LSE Group and Singapore Exchange have fallen victim to protectionist regulators in their most recent attempts at consolidation. The London exchange's tie-up with TMX, the Toronto exchange, collapsed after a rival consortium of Canadian banks and pension funds garnered political support in its native territory. A similar fate met Singapore Exchange's attempt at buying the ASX. Since then, however, Mr Rolet has made a series of strategic acquisitions, not least the €463m (£362m) takeover of LCH.Clearnet, the clearing house. That deal diversifies LSE Group's revenue streams, and will lead to licences in the US in the derivatives clearing space. In addition, the company bought the remaining 50pc stake in FTSE International it did not already own from Pearson for £450m. Earlier this week, LSE Group said that revenues in the three months to the end of June rose 10pc to £209.5m on a year-on-year basis. A spokesman for LSE Group declined to comment.