His term will come to an end after the annual meeting next July and he said his decision to make the announcement now was to give the LSE enough time to find a suitable successor.
Cruickshank has been widely criticised during his time at the helm, with his support for the merger with the German bourse raising plenty of eyebrows through the city.
Mark McMullen joins the private client services team from Smith & Williamson
Merger between Clear & Lane Chartered Accountants and Magma Chartered Accountants was finalised on 3 February
BDO has taken its new partner intake to 23 during the first half of its financial year, including the appointment of five partners in five weeks
The firm reports 7.6% global fee income growth for the year ending 31 December 2016