South Africa-focused bank Investec has agreed to pay £412m for the shares in British wealth manager Rensburg Sheppards that it does not already own.Under the terms of the recommended offer, Rensburg shareholders will receive 1.63 fully paid newly issued Investec shares in exchange for each fully paid Rensburg share currently held. Investec already owns about 47% of the group.The offer values each Rensburg share at 916 pence, a 48% premium to the closing mid-market price of 620 pence on 29 March.Stephen Koseff, chief executive of Investec, said: "Rensburg Sheppards has been a good investment for Investec over the past few years and the proposal we have announced today is the natural next step for both businesses. "Investec's wealth and asset management activities have grown strongly in recent times and we believe that Rensburg Sheppards will thrive as part of the Investec Group. We look forward to supporting Rensburg Sheppards and enhancing our strategic position by building an even stronger business in this core area of the market."