The Actis-led private equity consortium bidding for South Africa's leading pension consultancy has increased its offer by nearly 5% to 8.1bn rand (€873m), in what could be one of the country's largest buyout deals on record.

The consortium, led by UK emerging markets buyout group Actis, has increased its offer from 16.25 rand a share, to 17 rand a share, the company said in a statement to the Johannesburg Stock Exchange.