The life insurer announced today that it had bought up £6bn worth of annuity portfolio from Aegon's UK subsidiary, Scottish Equitable, under a reinsurance contract.
The deal covers roughly 187,000 policyholders, who will remain customers of Aegon for the time being.
The purchase of Aegon's UK annuities is the latest in a string of similar transactions for Rothesay Life, which reinsured £1.2bn of UK annuities from Zurich in 2015.
"As a specialist provider of annuities, I am delighted that Aegon has chosen Rothesay Life to secure its policyholders' pensions over the long term," said Addy Loudiadis, chief executive and founder of Rothesay Life. "This transaction represents a significant step for Rothesay Life taking total assets under management to over £20bn and total lives insured to over 400,000."
Alex Wynaendts, chief executive of Aegon, added: "I am very pleased that we have reached an agreement with Rothesay Life. This is an important step in the process to fully divest our UK annuity portfolio, and will enable us to focus on our fast-growing platform in the UK."
Also today, Rothesay Life revealed that it had turned a pre-tax profit of £347m for its year ended December 2015, up 42 per cent compared with the year before.
Loudiadis remarked: "Rothesay Life has delivered a record year for organic new business growth and profits against a backdrop of Solvency II uncertainty in 2015 for the industry. We have remained cautious with our investment strategy and been very selective in underwriting."