The fund house reported underlying pre-tax profit of £159.2m, up from £100.7m at the same time last year. Assets under management at the end of 2011 were £64.3bn, compared to £61.6bn a year earlier.
Within this, retail and institutional absolute return FUM more than doubled in the period, from £2.1bn to £4.5bn.
Henderson said the acquisition of Gartmore (completed on 4 April last year) had cemented its position as a UK retail fund manager.
David Jacob, managing director and CIO of the group, said: "Financially the acquisition has already delivered and we are starting to see the strategic benefits flow through. We have enhanced our product range, in particular our absolute return offering, and we are beginning to fill gaps in two priority areas – global equities and emerging markets equities."
The group saw positive net flows into a range of UK retail funds, including its absolute return, strategic and corporate bond funds and its multi-manager and cautiously managed funds.
"We continue to see good demand for our fixed income funds with three of our funds topping £1bn in assets. Anticipated market volatility in 2012 is likely to make investor demand difficult to predict, but we think that both fixed income and absolute return funds will remain in demand," Jacob added.
The AlphaGen funds, which used to be Gartmore funds, were resumed shortly after the acquisition and Henderson said it was particularly pleased by the flows into these.
Gartmore’s acquisition brought £15.7bn across in AUM, but this was partly offset by the divestment of non-core businesses amounting to £4bn.
But during the year the group also suffered net outflows of £6.4bn, with retail funds accounting for £1.4bn of this. It also lost £2.7bn in AUM through market and forex movements.
