Kirk is affiliated with the law firm Sullivan & Worcester LLP of Boston, Massachusetts, and was a partner from 1977 to 1990. He is the chairman and chief executive officer of Kirk & Associates, Inc., a business advisory and consulting firm located in Boston. He is also a member of the board of directors of the Hartford Financial Services Group, Inc., Rayonier, Incorporated, and Cedar Realty Trust, Inc. He was a board member of ITT Corporation from 1989 to 1997 and Bradley Real Estate, Inc. from 1991 to 2000.