Former Pennsylvania Gov. Edward G. Rendell returned to private practice last week with his former firm, Ballard Spahr, as a partner in its Energy and Project Finance Group. His practice will focus on public-private partnerships in the energy and environmental sectors, particularly on infrastructure development. “Ballard was always one of the best law firms in Philadelphia and its profile and strength as a national firm are greater than ever before,” Gov. Rendell said. “The firm had seven offices when I left in 2003. It now has 13. This is a great time to be coming back and I look forward to contributing to the firm’s growth and stature.”