Operating profit at the wealth and investment division fell 4.2% to £38.7m, however, even as the asset management business saw operating profit rise by 5% to £133.7m.
The asset management side of the business, which caters mainly for institutional clients also saw an increase in its AUM, but by a smaller figure of 4.7% up to £61.5bn.
Following the acquisition of Rensburg Sheppards in June 2010, a full contribution was made to the figures of the wealth and investment division.
But results were adversely impacted by restructuring of certain operations in the UK and Europe, including the sale of Rensburg Fund Mangers to Franklin Templeton.
Meanwhile, the acquisition of Evolution Group in December last year added approximately £7bn of assets and Investec said the business was integrating well.
The company, which is dual listed in London and South Africa, saw an overall slide of 17.4% in operating profit, down to £358.6m from £434.4m in 2011.
In its annual report, the firm said the year had "echoed the difficulties of the global macro-economic environment with volatile markets and low levels of activity negatively impacting results, particularly in the second half".
The UK and South African businesses were said to have performed in line with the prior year, while the Australian business (representing only 6.6% of assets) reported a loss as a result of weakened residential property prices, Investec said.
Investec added that in the challenging global market conditions, it would continue to pursue a strategy of realigning the business model towards less capital intensive activities.
This involves a focus on the asset and wealth management businesses and a move away from its specialist bank, which had a weak performance during the year.
"The confluence of the operating environment with that of enhanced regulation made for a particularly difficult year for the specialist bank. In light of this uncertainty we continue to hold our liquidity and capital positions at levels that are appropriate for the prevailing environment," the company said.
