As corporations make increased and more visible advances into the realm of social responsibility, many are seeking to form functional alliances with the non-governmental organizations (NGOs) they formerly considered adversaries. As such, PR agencies often must take on new roles in order to bring these two seemingly disparate groups together.

"One of the challenges when you bring together two organizations is bringing together two different cultures," says Chris Deri, head of Edelman's global CSR and sustainability practice. "From a simplistic starting ...