BlackRock (NYSE: BLK) earnings beat out analysts’ expectations as growing interest in exchange traded funds and high inflows into its iShares ETF division provided an extra boost.

The iShares branch is now the largest chunk of BlackRock’s base fee income, reports Brendan Conway for Barron’s.

BlackRock’s base fees now account for 88% of its $2.25 billion in reported revenues for the first quarter of 2012, up from 86% last year. Of the 88% or $1.98 billion in base fees, iShares now accounts for 24%, up from 22% last year, making the ETF division the company’s largest money maker.

The money manager saw Q1 earnings per share rise to $3.14 compared to $2.89 last year, according to Reuters.

Customers took out $10.3 billion from long-term funds in the first quarter. However, for iShares, customers added a net $18.2 billion, or a 74% jump year-over-year, with half of the assets going into bond-related ETFs.

Additionally, investors are engaging in what CEO Laurence Fink calls “de-risking” as more money is shifted from cash and short-term bonds to equities and longer-term debt. Still, Fink does not believe a “major shift” is evident in investors’ attitudes. [ETF Data: Outflows on Market Weakness]

For more information on the ETF industry, visit our current affairs category.

Max Chen contributed to this article.