NEW YORK (REUTERS) - BlackRock Inc, the world's largest asset manager, reported a lower-than-expected quarterly profit as new money moving into the company's long-term asset management business fell in a turbulent fourth quarter for investors.

BlackRock experienced total long-term net flows of US$53.87 billion (S$77.4 billion) in the three months ended Dec. 31, down from US$87.82 billion in the same quarter of 2014.

The New York-based company's net income rose to US$861 million, or US$5.11 per share, in the quarter from US$813 million, or US$4.77 per share, a year earlier.

On an adjusted basis, BlackRock earned US$4.75 per share, falling short of the average analyst estimate of US$4.80, according to Thomson Reuters I/B/E/S.

In the third quarter, rough markets and a higher tax bill contributed to an 8 percent drop in profit.

BlackRock's iShares exchange-traded funds business took in US$60.22 billion in new money in the latest quarter, up from US$44.19 billion a year earlier.

The lion's share invested in ETFs went into equities, driven by demand for U.S. stocks.

Across all of its products, BlackRock attracted a net US$53.47 billion in long-term equity investments. Net investment in fixed income was US$158 million, while US$464 million went into alternative investments.

BlackRock ended the quarter with US$4.65 trillion in assets under management, virtually unchanged from a year earlier.

Up to Thursday's close of US$310, BlackRock's shares had fallen about 9 per cent since the start of the year. For all of 2015, the stock fell nearly 5 per cent.