Increasing demand for income and non-correlated assets will help ETF inflows pass the $100-billion mark this year, according to a new report.

The 2011 Mid-Year SPDR ETF Outlook by State Street Global Advisors, the asset management division of State Street Corporation, reports that U.S. ETFs attracted $56.3 billion in new inflows during the first six months of 2011, up from $37.3 billion during the first half of 2010.

ETF investors increased their exposure to fixed-income, developed international markets and dividend strategies while shifting away from emerging markets and small cap equities during this  period, according to the report.

If ETF flows remain on their current pace, 2011 will mark the fifth consecutive year that ETFs attract more than $100 billion in positive cash flows, said Kevin Quigg, global head of the SPDR ETF Capital Markets Group at State Street Global Advisors.

"With demand for income and non-correlated assets on the rise, a growing universe of professional and retail investors are using ETFs to access precise sources of return and improve the diversification of their portfolios," Quigg said.