The world's biggest investment banks have begun to choose on which side of the deal table they will be sitting in negotiations over the future of the 215-year old London Stock Exchange.

The LSE and Germany's Deutsche Börse announced they were in advanced talks over a merger of equals on February 23. At the time, only two lead financial advisers were named, with Robey Warshaw representing the LSE and fellow independent Perella Weinberg working for Deutsche Börse.