BlackRock looks set to seal the acquisition of Barclays Global Investors and become the world’s biggest money manager by Wednesday, according to people close to the talks.

The US group plans to pay Barclays $12bn-$13bn (£7.5bn-£8.1bn) for BGI – half in cash and half in shares – to create a group with more than $3,000bn in assets under management, half as much again as nearest rivals such as State Street, Allianz and Fidelity.