Following on the solid 24 percent yearly gains in 2012, commercial investments notched a strong first quarter. Sales of major properties totaled $72.8 billion in the first quarter, a 35 percent rise from a year ago, according to Real Capital Analytics. Portfolio transactions made up a large portion of the volume, especially due to the sale of Archstone apartment properties to Equity Residential and Avalon Bay. Individual property sales comprised $40 billion, a 7.8 percent gain from the same quarter last year.