Anglo-Australian fund manager Henderson Group posted lower-than-expected profits in the first half as outflows accelerated in the second quarter on volatile markets and "fragile" investor confidence.Henderson said pre-tax profit was £41.6m in the first six months.That compared to its own estimate of between £47m and £49m.Last month the fund manager announced it had pulled out of talks to take over US boutique RidgeWorth from SunTrust.Over the period, Henderson posted net outflows of £1.3bn comapred with £600m in the first quarter. Analysts had expected outflows to range between £700m and £900m in the second quarter.Assets under management were £56.4bn, down from £60.3bnat the end of the first quarter."We expect market volatility to continue in the second half, though the business trends seen so far this year remain intact," said chief executive Andrew Formica, who describe investors' confidence as "fragile."