The £140 million acquisition, announced in August, will add some £77.5 billion of assets to the Edinburgh-based firm’s books, creating the UK’s largest platform business.
Aegon UK chief executive Adrian Grace said: “Today marks the start of a new era for both Aegon and Cofunds. The completion takes us a major step further in our transition from traditional life company to fully-fledged platform business.
“Our focus now is to help intermediaries grow their business, grow their profitability and manage their risk and costs effectively. What will set us apart from the competition is our commitment not to compete with advisers for distribution, and focus on our investment trading platform and providing the best service and tools.”
Cofunds’ users will benefit from a wider product range, including access to exchange-traded funds, investment trusts, shares and an integrated pension, Grace said.
Existing Aegon platform customers will see additional functionality – such as the pre-funding of trades, debit card acceptance and an improved investment selection process – begin to roll out in the second half of the year.
Grace added: “By discussing our approach and progress with intermediaries from the outset, we aim to deliver a platform that they feel invested in for the benefit of their business and their clients.
“While we recognise that we have a big task at hand which needs to be handled with care, it represents a fantastic opportunity to work with intermediaries to shape the future of the platform industry.”
Dutch-owned Aegon, based at Edinburgh Park, employs about 2,100 people. The takeover of Cofunds follows its acquisition of BlackRock’s UK platform and the sale of its £3bn UK annuities portfolio to Legal & General in May.