Described by colleagues as "a very rich young man", Mr O'Donnell, 36, worked at NatWest before joining HSBC, where he has worked in his present transatlantic role for the last three years. The native New Yorker will give up control of the UK equities division this month and finally leave the bank in New York next summer.
His boss, Bernard Asher, says he wanted to inform staff of Mr O'Donnell's decision to leave the bank immediately rather than letting it leak out slowly. Mr Asher said: "He's been thinking about it for a considerable period. Its touching to see someone with such a vocation."
No successor has been selected yet, so Mr O'Donnell's deputy, Krishna Patel, will take over his responsibilities in the interim.
Speaking of leading City figures with vocations, it is a little known fact about Bob Diamond, chief executive of Barclays Capital (the investment banking division of the Barclays Group), that he was once a teacher. Mr Diamond fully intends to return to the groves of academe when he's finally had enough of the high stress world of capital markets.
So he was in his element yesterday showing a party of children from King Alfred's School in North London around the trading floor at Barclays Capital, Canary Wharf.
"Your telephone bill must be very large," said one child on being told that part of the function of a trader is to burn the telephone line 24 hours a day to his counterparts in Tokyo, New York and Hong Kong.
Another asked for advice on how to invest his pocket money. "A potential client," Mr Diamond gleefully proclaimed, hugging the child warmly. But the best question came from the boy who asked: "If you're chief executive, how come you look so young?" The challenge of revitalising Barclays Capital after the sale of BZW's equities and corporate finance businesses is plainly agreeing with Mr Diamond.
Robin Ellison, a partner with the law firm Eversheds, has been reported to the police by his local council for criminal damage, after he was allegedly seen painting over double yellow lines outside his home in Hampstead, London.
The strange incident happened last month during a legal dispute between Camden Council and Mr Ellison, according to The Lawyer magazine. The council wants to use the land as an access point for six units of "affordable housing".
A council employee, who was passing by, claims she saw a man fitting Mr Ellison's description, wearing jeans and a woolly jumper, brushing black point over the double yellow lines at the crack of dawn.
Earlier, according to Camden Council, Mr Ellison had erected bollards on the land, claiming it was his.
When the Council tried to remove them he took out an ex parte injunction. The injunction was overturned, and earlier this month he discontinued his claim to prove ownership of the land a week before the trial. Mr Ellison agreed to pay the council's costs.
Mr Ellison was unavailable for comment yesterday.
John Rudgard has selected Michael Hughes, formerly of Guinness, to succeed him next January as chief executive of Bulmers, the cider maker which Mr Rudgard has served for the last 33 years.
"I'm standing down at my own request. I've been chief executive for the last 10 years and I think it's time to hand over to a younger man," Mr Rudgard said yesterday.
When he retires next year at the age of 58 Mr Rudgard will carry on with the usual mix of non-executive directorships and private investments common to senior businessmen. He will also devote more time to his one-ton sailing boat, called the Isithotinhere?
"It got its name because the only thing my wife and I argue about is the temperature inside our house," says Mr Rudgard.
British Steel may be the highest yielding stock in the Footsie but there is one group of investors who don't seem to care that the shares have gone nowhere in the last 10 years. US investors now own 40 per cent of the company, having more than doubled their shareholdings in the last 11 months, oblivious to the meltdown in profits.
To thank them for their unstinting support, the British Steel chairman Sir Brian Moffat last night flew out to New York to host a slap-up dinner, organised by Goldman Sachs and the Twenty One Club.