Around 40 people will lose their jobs as the result of Endurance Specialty Holdings' takeover of Montpelier Reinsurance, according to one source who claimed to have knowledge of the matter.

The source, who said she was a relative of one of those to lose their job, claimed a further 27 ex-Montpelier staff were retained by Endurance.

An Endurance spokeswoman declined to confirm or deny the numbers given by the source.

Endurance bought its fellow Bermuda insurer and reinsurer for around $1.9 billion and the deal closed last Friday. This week, many Montpelier employees learnt their fate.

In an e-mailed statement, an Endurance spokeswoman wrote: “For those Montpelier employees who are not being retained, we are providing severance, prorated bonuses for the part of the year worked, local outplacement services, and we are keeping them on our payroll and benefits through their notice periods (instead of paying in lieu of).”

The retained staff moved into Endurance's offices in Waterloo House yesterday, vacating Montpelier's nearby offices in the Waterfront complex on Pitts Bay Road.

As reported by this newspaper earlier this week, nearly half of Montpelier's global staff of 185 will be retained.

In a conference call, Mike McGuire, Endurance's chief financial officer, told analysts that the cost savings achieved by the amalgamation would be greater than the company had first anticipated.

“Based on the detailed integration planning we have already conducted, we now believe we will be able to achieve, by the end of 2016, annual run rate expense savings exceeding $70 million compared to the $60 million we originally estimated,” Mr McGuire said.

“This represents approximately 57 per cent of Montpelier's actual 2014 general administrative expenses. We clearly have a lot of work to do over the coming month and quarters to achieve this, but our integration process is already well under way.”

John Charman, Endurance's chairman and chief executive officer, added in Tuesday's call: “Since March we have worked diligently with Montpelier's staff to plan for a quick and effective integration of our businesses. And that integration plan has already been put into action.

“We are committed to completing the integration as quickly as possible and with that in mind we have already informed the vast majority of Montpelier employees of their status going forward. As of yesterday, we are now all working together and moving forward as a much stronger and better positioned company.”

Mr Charman said the addition of Montpelier's Lloyd's operation and its Blue Capital third-party capital arm “enables us to be immediately more relevant” to clients and brokers.