The number of Wellington employees who are defecting to rival Lloyd's managing agents has risen again this week following Catlin's decision to take over the insurer.

Wellington is understood to be on the brink of losing its bloodstock/livestock account after the departure of its deputy underwriter, Alex Colquhoun.

Colquhoun has left the division, which writes around £10m in premium and represents about 1% of the insurer's income, to join fellow Lloyd's agency, Talbot.

His departure comes after underwriting assistant, Lorraine Allen, left the four-strong team. But head of the division, Peter Carter, is said to have temporarily shelved plans to retire at the end of the year, after being retained until July 2007 to help run-off the remaining business.

A senior Lloyd's source told Insurance Times that defections from the company could continue with speculation that its aviation team is also looking to move to another market insurer.

"[Wellington] is not going to keep a lot of the people that it wants to," he said. "I suspect that in the case of the UK commercial property team [which recently left en masse to join Novae], they would have preferred them not to go, as Catlin does not have anything like that, whereas with the bloodstock division it is probably not as concerned."

Catlin's proposed takeover of Wellington is expected to be completed on 19 December. A source close to Wellington predicted that once the deal is finalised further job losses would follow.

He said: "There is likely to be a major carve out of Wellington's back office, such as IT, finance and probably technological support."

Wellington declined to comment on staffing issues.