PS Business Parks Inc. reported net income to shareholders plummeted to $3.5 million or $0.16 per share for the third quarter ended Sept. 30 compared to $14.3 million or $0.65 per share in the like period a year ago. The Glendale-based real estate investment trust saw revenues increase to $61.8 million compared to $54.8 million for the third quarter of 2005.