Equity Residential (EQR) earned about $113 million for the third quarter, up from $29.8 million last year due in part to an increased demand for apartments, the company announced Wednesday. The Chicago-based real estate investment trust reported income of 35 cents per share for the quarter. The number of tenant households rose 4% in the year ending June 2011, according to the Census Bureau. “Fundamentals continue to be positive and we remain confident that increasing demand for apartment living combined with limited new supply will produce strong results next year and for years to come despite concerns about weakening economic growth,” President and CEO David Neithercut said. Equity Residential attributed the uptick in earnings primarily to higher gains from property sales in 2011. The company acquired two properties for $113 million and sold seven properties for $210.1 million during the quarter. Write to Andrew Scoggin. Follow him on Twitter @ascoggin.