According to the Investment Company Institute (ICI), the combined assets of U.S. exchange-traded funds fell $32.25 billion to $578.07 billion in June.

Even though this is a 5.3 percent decrease compared to May, on a year-over-year basis ETF assets have climbed by 19 percent or $92.14 billion compared to June 2007.

During June, the value of all ETF shares issued exceeded that of shares redeemed by $10.34 billion. In June 2007, ETFs have experienced a net issuance of $5.30 billion.

Not included in the data are exchange-traded notes, which are debt securities. As of the second quarter, there’s around 80 ETNs with close to $6 billion in total assets.

ICI is a national association of U.S. registered investment companies.

Ron DeLegge is the San Diego-based editor of www.etfguide.com.