The bank is expected to announce as soon as Monday that headhunters are being appointed to find a new finance director but that Lucas could stay as long as 12 months while a successor is found.
Lucas, who joined the board in April 2007, started discussing his retirement with the new chief executive, Antony Jenkins, before Christmas. Jenkins was promoted after Bob Diamond quit in the wake of the £290m fine for rigging the benchmark interest rate while the chairman, Marcus Agius, has been replaced by Sir David Walker.
The intention of Lucas to retire is being announced at a time when he is under investigation by the Financial Services Authority about disclosures the bank made in 2008 when it embarked on two crucial fundraisings, largely with Middle Eastern investors, that allowed the bank to avoid taxpayer bailouts.
The FSA's investigators are focusing on a fundraising in June 2008, when the bank raised £4.5bn through an issue of new shares, and a second fundraising, in November 2008, when it raised more than £7bn, and focusing on "disclosure in relation to fees payable under certain commercial agreements" at the time.
The Serious Fraud Office also launched an investigation in August last year into possible payments by Barclays when it secured the lifelines, while on Friday the Financial Times reported that one element of the inquiry concerns whether Barclays may have lent Qatar funds to buy shares in the bank.
Barclays declined to comment on Sunday.
Lucas joined the board in April 2007 – just months before the credit crunch crippled the financial system – from PricewaterhouseCoopers, where he used to be the Barclays auditor. The bank has stressed its does not believe anything was remiss and that it "is satisfied its disclosure obligations and confirms that it will co-operate fully with the FSA's investigation".
Lucas is one of four current and former Barclays bankers involved in the FSA investigation. In July, the bank had stunned the City by announcing the FSA had "commenced an investigation involving Barclays and four current and former senior employees, including Chris Lucas".
His planned departure is being announced just as Jenkins puts the finishes touches to his strategy day on 12 February and just days before Jenkins appears before the banking standards commission to face questions about the culture of banking. Jenkins waived his potential £1m or more bonus on Friday before giving evidence, citing "multiple issues of our own making besetting the bank". Lucas had already waived his 2012 bonus following the £290m Libor fine.
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