Last year's £365 million takeover of rival fund manager Gartmore helped Henderson power profits ahead in 2011.
But chief executive Andrew Formica said the recent surge in equity markets since the start of the year had yet to drive significant demand from retail investors.
He said UK punters remain risk averse and are still choosing bond funds over equity funds, but there are signs an appetite for shares may be improving. European investors had moved back into equities quicker.
Formica said: "The acquisition of Gartmore has exceeded our expectations on all counts and made a significant contribution to these results. Market conditions remain uncertain, but I am confident about the outlook for the Henderson Group.
"We have succeeded in strengthening both our business and client offerings and are well equipped to continue to deliver good returns for our investors through this volatility."
Henderson's headline profits rose 58% to
£159.2 million while assets under management rose 4% to £64.3 billion.
