Aviva has renewed its wrap administration deal with Citi that takes the partnership through to 2022.
The firm said the news reflected its long-term commitment to the platform market.
Citi provides admin through its OpenWealth service, which covers record keeping, transaction management and reporting.
Aviva's intermediary director Andy Beswick said: "Citi's expertise in this market allows us to offer a flexible proposition at a competitive price, while retaining the same robust platform service from them.
"Aviva's platform offering is designed to help advisers manage their clients' portfolios efficiently, compliantly and profitably. Tools like model portfolios, individual and bulk switching and rebalancing - all help advisers control the cost of serving their clients.
"We're continuously looking to improve our platform and our agreement with Citi means we have a long-term partner with whom we can grow this part of our business."
Citi's EMEA head of securities and fund services Sanjiv Sawhney added: "We are delighted to extend our business with Aviva and this appointment is testament to the high quality of the wealth management services that we have been delivering.
"This mandate is a significant step towards our objective to establish OpenWealth as a leading player in the wrap administration market."
The Aviva wrap broke through the £1bn AUA last week, a growth of 53% since the beginning of the year.
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