The UK's government-backed savings scheme National Savings & Investment (NS&I) has put out a tender for an outsourcing deal that could be worth up to £2 billion for the successful bidder.
The agency - which has 26 million customers - is looking for a partner to manage processing across the full spectrum of its operations, including IT, call centres and back office transactions.
The new contract is set to start in 2014, following the expiry of a 15-year deal with Siemens IT Solutions and Services.
A spokesman for NS&I told the Guardian broadsheet that the contract would last for eight years, with an option to extend for a further three, and would have a value ranging from £1.25bn to £2bn.
The winner of the contract would have the opportunity to extend its reach into other government departments which use NS&I's transaction processing services.