Life and pensions group Friends Provident said that it is to axe around 600 jobs as part of a group-wide overhaul and cost-cutting drive.
The insurer said the jobs would go throughout its core business in the UK and internationally by the end of 2009 as it seeks to save nearly £60 million.
Friends Provident added that it will also look at outsourcing and is considering offloading parts of the firm, including its investment business F&C Asset Management, which is thought to be worth around £500 million.
Excluding F&C Asset Management, the company employs almost 4,000 people.
The Unite union said it was "deeply concerned" about the plans to axe 600 jobs.
Deputy general secretary Graham Goddard said: "The news that jobs from across the business are to be lost is extremely disappointing and Unite will strongly oppose any compulsory redundancies.
"The current climate in the financial services sector means that employees are increasingly anxious and insecure about their future.
"We will be seeking further negotiations and meetings with Friends Provident."
