(ShareCast News) - FTSE 250 investment company Alliance Trust reported a rise in assets under management at its investment arm as it lifted its dividend for the 49th consecutive year.For the year to the end of December, assets under management at Alliance Trust Investments rose 9% to £2.1bn.The net asset value total return for the trust was 5.4% in 2015, which was above the MSC ACWI benchmark return of 3.8%, and the company raised its dividend by 0.05p to 12.43p.Chairman Lord Smith of Kelvin said: "2015 was an eventful year for Alliance Trust and highlighted that shareholders expected change. In order to deliver this, we set out a package of changes on 1 October to enhance shareholder value and the process to implement them is well under way."We have already made good progress. In particular, the investment team is continuing to deliver improved investment returns, significantly outperforming the benchmark. At the same time the discount to NAV has narrowed and we are on target to achieve our cost cutting objectives."Also on Friday, the company noted the lack of gender diversity on its current board following the departure of a number of directors since the last annual general meeting and said it was determined to address the issue at the earliest opportunity.Richard Troue, head of investment analysis at Hargreaves Lansdown, said: "Some progress has been made bringing the trust back to its roots - a core, low-cost global equity portfolio that is well diversified, capable of steady growth and a rising income. Shareholders will be pleased to see some outperformance, though one swallow doesn't make a summer. It's still early days for the investment team, but they are off to a positive start."At 0812 GMT, Alliance Trust shares were up 0.6% to 503p.