The London Stock Exchange (LSE) was suddenly left without a finance director today when Jonathan Howell quit after 11 years at the business for Close Brothers, the UK investment bank.

Mr Howell, who was paid £972,000 in salary and bonuses last year, is walking away from the LSE with 229,188 shares worth £3.9 million at today's price of £16.99.

He also holds options to buy further shares and could qualify for a bonus payment covering the six months since the exchange's year-end in March.

Mr Howell had been on the board of the exchange for eight years.

Together with the chairman of the LSE, Chris Gibson-Smith, and Clara Furse, the chief executive, Mr Howell was one of only three executives whose new jobs had been formally allocated after the completion of the £1.6 billion merger with Borsa Italiana only last week.

Before joining the LSE, initially as its head of regulation, Mr Howell worked at PricewaterhouseCoopers, the accountancy firm, as an accountant.

Following last week's exits of Gary Allen and Peter Meinertzhagen, Mr Howell had become the LSE's longest serving director, joining the exchange in 1999, when it was still a mutual owned by its members.

Mr Howell presided over the exchange's books during its landmark flotation, and he was the LSE's financial gatekeeper while no fewer than five potential buyers circled the exchange over a period of about seven years.

Nasdaq, the US exchange, Macquarie, the Australian bank, and rival exchanges Deutsche Borse and OMX all launched formal bids. Euronext, now owned by the New York Stock Exchange, indicated its interest but did not launch a formal offer.

Mr Howell is likely to join Close, where he will become finance director, in February.

By then the LSE will be eligible to become a blue-chip member of its own FTSE 100 index.

Ms Furse said: "Jonathan has played a central role in the exchange's transition from mutual organisation to highly successful public company.

"Having worked with him for over six years, I will miss his sound financial, commercial and strategic judgment."

A spokesman said Mr Howell was looking for "a new challenge" and that relations between the LSE and its departing director were "very amicable".

The LSE said that it had begun "an external search" for Mr Howell's successor.

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