The finance industry was hit with a pre-Christmas jobs blow today with news of more than 700 job losses.
The Accord trade union said the jobs will go at Lloyds Banking Groups offices in Aylesbury, Buckinghamshire.
Lloyds will move 570 life, pensions and investments administration jobs, while Equitable Life has given notice that its contract with Lloyds for admin services will come to an end in March 2011.
The work will transfer to Indian firm HCL, with the 340 employees carrying out the work being transferred to HCL, which will only retain 100 staff.
The union said the combined decisions will result in more than 700 job losses in Aylesbury by the end of 2011.
Ged Nichols, general secretary of Accord, said: "Today's announcements are a body blow for the workforce and for Aylesbury particularly as the Lloyds Banking Group is the largest private sector employer in the town.
"Our main concern is to avoid compulsory redundancies arising from any part of today's announcements.
"The terms and conditions of employment for those staff who Equitable Life are proposing to transfer to HCL is also a priority."
Mr Nichols said the union was seeking legal advice about the proposed transfer of staff.
Chris Wiscarson, chief executive of Equitable Life, said: "This is one of the most important decisions in the society's history.
"HCL has an impressive reputation and I am confident they will provide great service and great value to policy holders.
"I very much regret the concern, uncertainty and disruption these changes will cause for many people in Aylesbury.
"We will keep these people fully informed and supported over the next 15 months to help them plan for their future as effectively as possible."
Earlier this month Lloyds announced that 5,000 jobs will go in 2010 on top of 10,000 already cut this year.
The bank said 5,000 jobs will be hit by changes within its group operations, insurance and retail divisions by the end of next year.