John Grimbleby, head of Aon's 100-strong marine operation in Leeds, is one of several high-profile redundancies as part of the giant broker's first wave of cut-backs.
Aon announced last November that it would axe 1,000 UK staff and 2,000 in other countries in a bid to streamline its operations after it blazed a massive acquisition trail over the past several years.
Market sources said six positions, five of which are at director level, have been made redundant in the marine and energy reinsurance division.
At least two director titles and a further two other jobs in the non-marine reinsurance are also thought to have been removed.
In addition, eight redundancies up to the role of associate director are thought to have been made in Aon's Romford and Leicester offices in the broker services administration area.
Insiders have reported that staff are being told to go on gardening leave immediately.
Aon's Romford office is believed to be under management review.
A spokesman said: “We are hoping for ‘natural wastage' – that people will be able to go because they want to go.
“Furthermore, Aon has put together settlement arrangements that exceed statutory requirements. Retraining and placement schemes are also being offered to employees.”
He said people in junior and senior positions were being told to clear their desks, but was unable to comment on the number of staff involved.