Aberdeen Asset Management has been hit by another wave of outflows from its flagship global and emerging market funds, as investors continue to fret about the impact of a US rate rise on dollar-indebted economies.

Net outflows in the first half rose to £11.8billion, up by £2.5bn from a year earlier. Chief executive Martin Gilbert said he believed a US rate rise was further away than many people suggested, but admitted life would remain tough for Aberdeen "until emerging markets come back into fashion". He described the latest surge of outflows as "torrid", but cited "some structural outflows from certain clients".

It was the eighth successive quarter of net outflows from Aberdeen, following the "taper tantrums" market response to the first hint of a turn in the US cycle two years ago. The group's shares have since been volatile, with the past 12 months seeing a low of 390p in October and a high of 507p last month. They slipped 11.9p to 451.2p yesterday. But the three-year record shows Aberdeen is up 75per cent against a 26per cent uplift for the FTSE-100.

Mr Gilbert stressed: "I am pleased to report that the group has increased its underlying profits by 25per cent as we benefited from the diversifying effects of the acquisition of Scottish Widows Investment Partnership, which we completed a year ago. We remain strongly cash generative and we again increased our dividend, whilst also adding to our regulatory capital headroom."

Pre-tax profits rose to £270million, while total assets continued to move forward, to £331bn, thanks to £4bn of foreign exchange benefits and £13.5bn from market movements, a rise of 2 per cent since September 2014.

The dividend is raised by 11per cent to 7.5p and the group is to plough up to £100m into buying back its own shares during the year, after seeing its surplus capital rise to £221m.

Bill Rattray, finance director, commented: "What we want to do is strike a balance between reinvesting in the business and returning excess capital to shareholders." The aim was a steadily rising dividend rather than any special payouts, he added.

Shore Capital said the buyback exercise was "value-neutral" at current share price levels, and maintained its 463p price target on the shares.

RBC Capital Markets which downgraded the stock last month said it "could not see flows improving".

The integration of SWIP drove a 2per cent fall in operating costs and a rise in operating margin to 44.7 per cent from last year's 43.9per cent.

Mr Rattray said the incremental margin from the SWIP deal had been targeted at 55per cent by the end of this year but had already hit 60per cent. The group was "a little bit ahead of the game there", he said, but suggested the effect on Edinburgh-based SWIP's employee numbers had been "pretty much in line with expectations".

On Aberdeen's fund performance, which has suffered from being underweight in the US and Japan, Mr Rattray commented: "The team are still pretty comfortable with the stocks they do hold in portfolios, we build them from the bottom up rather than taking a view on markets."

Although emerging markets are seen as Aberdeen's strength or vulnerability, it it was global equities which saw a sudden acceleration of net outflows in the last quarter, of £2.4bn against only £611m for emerging market equities. The £11.3bn of net outflows included £3.5bn from SWIP, and £3.8bn from Aberdeen equities (£2bn from global and £1.6bn from emerging markets), with the balance coming from fixed income (£2bn) Aberdeen Solutions, (£1.2bn) and property (£720m).

Mr Rattray commented: "Investor sentiment towards emerging markets is still bit subdued, we have continued to see investors taking macro-calls, taking money out of the region." But he said the mood had been "more settled" with the exception of December, while in global equities there had been "a reasonably chunky withdrawal towards the end of the period" by one client.