May joins WS this month in a one-day-a-week role and is expected to work with UK and Ireland chief executive Colin Byrne on developing a cross-practice CSR consulting group.
Byrne said May, who will sit on the agency’s UK board of management, was taking up an important new role.
He added: ‘CSR is now an important facet of all corporate communications – with investors, governments and regulators, staff, customers and consumers.’