Insurance group Prudential is to close its Belfast office where 500 workers are employed at the end of next year and transfer work to other sites, including India. Another 200 jobs are to go in Bristol and London as part of a £40 million (€57. 3 million) cost-saving initiative.

Trade union Amicus pledged to fight the move, raising the threat of strikes to protect the UK workers' jobs. Prudential said work will be transferred to Craigforth in Scotland, Derby and Mumbai in India.

Chief executive Nick Prettejohn said: "Today's announcement continues our policy of establishing core sites in the UK business and building on strengths while delivering a cost-savings programme.

"These reorganisation proposals are an important step in delivering the cost savings that will enable the UK business to continue to build. Any change that results in redundancies is regrettable. We are consulting with unions and staff organisations and will make every effort to ensure that our people are kept informed and helped through this difficult transition period."

The Belfast office, which employs 500 staff, will close by the end of next year, while the Bristol office, which employs 40, will close in a year's time. Work at the central London head office of Egg, the internet bank owned by Prudential which employs 120 people, will be relocated to other offices in the capital.

The insurance firm employs around 5,800 people in the UK and a further 1,115 at a customer service centre in India.

SDLP South Belfast MP Alasdair McDonnell expressed "deep dismay" at the decision.

"This is a shock announcement that will hit many people very hard. The company has been providing jobs at Clarendon Dock since 1999," he said.