Capita chief executive Andy Parker is to step down as the troubled outsourcer reported a hefty fall in full-year profits.
The group, which has issued a string of profit warnings under Mr Parker's watch, said pre-tax profits fell 33% to £74.8 million and 19% on an underlying basis to £475.3 million.
Capita said Mr Parker will leave the company later this year in order to "pursue the next phase of his career" once a successor has been found.
The outsourcer has been stung by lower-than-expected revenues from major contracts, a slowdown in new orders and trading woes in its IT enterprise services business.
Chairman Sir Ian Powell said of Mr Parker: "He has made a significant contribution throughout his career at Capita and been instrumental in building the software, technology, and digital capabilities of the company.
"Andy's dedication to the company remains strong and he will actively support the board in the process to identify a successor."
Capita said in a September profit warning the Brexit vote was partly to blame for a slowdown in trading, amid ''continued delays in client decision-making''.
The firm again cited client delays on Thursday "which were likely compounded by the UK's referendum decision to leave the EU market".
The announcement comes after a difficult 2016 for the group, which has seen shares plunge to 10-year lows after sounding the alarm over profits.
In February Capita wrote off £50 million of historic contracts from 2012 to 2014, although some dated as far back as 2009.
Full-year revenue ticked up 1% to £4.9 billion.
Shares in Capita tumbled 7.5% in morning trading, piling further misery onto the firm, and comes after a downgrade to the FTSE 250 following a quarterly stock market shake up.
Russ Mould, director at AJ Bell, said: "Outsourcing group Capita's demotion from the blue-chip index has been followed by disappointing full-year results and the impending departure of chief executive Andy Parker.
"He has pledged quick and decisive action to simplify the business, strengthen the balance sheet, and return the group to profitable growth - but the structural changes will ultimately be overseen by a new CEO."