The marriage of the London Stock Exchange and Deutsche Börse may not be stone dead but that’s the way to bet, as Damon Runyan would have said. This so-called ‘merger of equals’ — with the Germans holding the larger stake and the top job but with the head office in London, at least to begin with — has foundered over a demand from EU competition authorities that the LSE should sell its majority stake in MTS, an Italian bond-trading platform.