BlackRock Inc.’s third-quarter profit rose a greater-than-expected 46 percent as the asset-management giant benefited from higher assets under management and a greater risk appetite among investors.

The better numbers were also helped by cost controls and a tax-related gain as BlackRock’s revenue fell 13 percent from a year earlier.

“Clients are putting money back to work in the markets,” said Chairman and CEO Laurence D. Fink.

BlackRock, the biggest public asset manager in the US with a market cap of more than $30 billion, earned $317 million, or $2.27 a share, compared with $217 million, or $1.59 a share, a year earlier. Revenue fell 13 percent to $1.14 billion.