CDR owner Incepta listed Macquarie as a client in October 2004, but the agency is thought to be retained by the bank only in Asia.
As PRWeek went to press Macquarie had yet to make an offer for the LSE. But the City has been rife with speculation that the group would pay more than the 530p a share proposed by Deutsche Börse in December last year, which kicked off the current takeover battle.
The LSE, which retains Finsbury, would need to be convinced by an offer from Macquarie, which has courted possible bid partners.
Deutsche Börse, which retains The Maitland Consultancy, subsequently withdrew its indicative offer after a shareholder rebellion.
However, the German group has reserved the right to make an offer for the LSE if other suitors emerge.
The Competition Commission is currently considering the Deutsche Börse takeover proposal and another from continental exchange Euronext, which retains Brunswick.