For the first time in its history the BBC has outsourced work abroad following a deal that will see workers in India dealing with BBC finances.
The corporation has handed an £85m contract to process its expenses and pay for production staff and stars to outsourcing giant Xansa.
The deal runs for 10 years and replaces the Medas financial system, which was introduced in 1997.
Although the BBC claims the contract with Xansa will save around £200m, unions said they had security concerns over payroll details of the corporation's 26,000 staff being transferred abroad.
Technicians' union BECTU also fears job cuts among the 300 BBC staff who were outsourced to Medas and is calling for a meeting with the corporation about their future.
Bectu official Luke Crawley said: "We're concerned on two different levels. We have members who have now been outsourced twice. We think off-shoring will inevitably lead to redundancies and we are seeking an early meeting with management about this.
"Our second concern is about BBC staff's payroll details going off-shore. We're very worried in light of a recent Channel 4 dispatches programme about how easy it is to obtain people's financial information if their payroll details transfer abroad."
The BBC's group finance director, Zarin Patel, said: "I believe this is an excellent deal for the BBC, and I am confident that Xansa will help us further to transform our finance and business processes.
"By moving our transaction processing to India, we are demonstrating that we are prepared to take bold and imaginative decisions that offer the licence-fee payer great value for money, while still maintaining the highest quality of service delivery."
BBC staff told Mediaguardian.co.uk that Medas had not delivered the level of savings expected and that there had also been problems and delays processing expenses and payments.
Last year Medas's parent EDS and the BBC denied to Mediaguardian.co.uk that there were problems with the system and that the contract would be re-tendered before the current deal had expired.
When the contract came up for renewal, EDS was invited to reapply but it is understood that those working for Medas were told it was unlikely it would win the contract again.
The BBC defended the deal saying: "This will be a major contribution to the BBC's target of releasing £355m of savings to invest in programmes and services.
"The BBC is currently conducting a simplification of its business processes as part of its Future Finance programme, which is delivering further savings of £17m.
"Xansa will provide their services from a blend of locations in the UK and India. All voice contact [customer support] with Xansa will remain in the UK; other services, including transaction processing, will be carried out at Xansa's location in Chennai, India.
"In this way, the BBC is taking advantage of the significant savings of globalisation while maintaining the benefits of more local customer support."
It added: "Xansa was selected from a shortlist of four companies [Capita, EDS, Infosys BPO and Xansa] after a rigorous evaluation process against a number of criteria which included value for money, cultural alignment with the BBC, service delivery capability, the ability to drive improvements to the BBC's business and financial processes, and transition and exit planning."
Xansa is a UK-based outsourcing and technology company with more than 8000 people in the UK and India.