PwC UK is to replace Deloitte UK as FTSE 100 independent financial service provider Hargreaves Lansdown Group's auditor from 24 October 2013.
The move is still subject to shareholder approval.
Deloitte only replaced EY as Hargreaves Lansdown's auditor in 2006.
Ian Gorham, chief executive officer of Hargreaves Lansdown explained: "The board recognises the potential familiarity risk of having the same auditors for a prolonged period and we felt that now was a good time to change."
On the current debate surrounding audit rotation, Gorham said: "We would prefer to have the flexibility to be able to change our auditors when it makes sense and we wish to do so.
"However, any reputable company should review their audit arrangements regularly. The contribution and objectivity of an external auditor must surely reduce with time and familiarity, however good they are."
The UK Competition Commission (CC) issued its provisional remedies for the UK statutory audit market last week suggesting five year mandatory retendering for FTSE350 companies.
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