Around 60 customer service jobs are being moved to Legal and General’s offices in Hove.
It follows the announcement that the insurance and investment group would close its Ipswich office.
Around 20 staff will be made redundant and 60 will have the option of relocating to Hove, with another 60 being offered relocation to Birmingham.
New jobs will be created in Sussex if staff members choose not to move.
Legal and General said a consultation into the office closure was ongoing and it was uncertain how many staff would relocate.
The move follows a restructuring of the group’s insurance business and combining of UK Retail Protection, General Insurance, Legal and General Netherlands and Legal and General Network.
A spokesman said: “This reorganisation has led to us making some further changes to our various operations and activities in our customer service areas, which means that all household claims will move from our Ipswich office, to create one single claims operation based in Birmingham and all Ipswich Customer Service operations will move to our Hove customer service location, creating a dual household customer service operation with Birmingham.
“We are confident these changes will reduce complexity, help us to improve our overall efficiency and enhance customer experience.”
Unite regional officer Ian Methven said: “We are calling on the senior management to reverse this unnecessary decision and industrial action to save these jobs can’t be ruled out at this stage.
“Unite firmly believes that Legal and General’s current strategy of reducing jobs to cut costs is damaging to both the business and to its members (policy holders). It is a counter-productive policy.”