Lloyds Banking Group has awarded £30bn of the £109bn it stripped from Aberdeen Standard Investments to BlackRock.
The assets, which are administered by Scottish Widows, were removed from Aberdeen Standard Investments when Aberdeen Asset Management, which had managed the money, merged with Standard Life.
Lloyds decided Standard Life’s insurance business was a competitor to Scottish Widows so invoked a clause in the contract to withdraw the assets.
Four firms, Schroders, JP Morgan, BlackRock and Goldman Sachs initially bid to manage the assets.
In addition to the £30bn mandate, Scottish Widows is pursuing a strategic partnership with BlackRock which includes collaborating in alternative asset classes, risk management and investment technology.
Antonio Lorenzo, chief executive of Scottish Widows and group director of insurance and wealth, said: "BlackRock has been selected following a competitive tender process in which it clearly demonstrated its global market leading capabilities and deep expertise in the UK market.
"The partnership will ensure that Scottish Widows and the group can deliver good investment outcomes for its customers over the coming years."
The company said it was close to making an announcement on the management of the remaining £80bn of assets.
Earlier this week it emerged Schroders and Lloyds were in discussions about a collaboration between their respective wealth management businesses, with a link-up potentially associated with the destination of the £80bn of assets.
Aberdeen Standard Investments disputes the right of Lloyds to withdraw the assets, and an arbitration process is underway.
BlackRock’s contract to manage the assets will start at the end either of the arbitration process or the contract, whichever is the sooner.