Michael Duff, Conor McCaughan and Melanie Rockcliffe have formed a partnership creating TROIKA, a new talent agency offering a bespoke service for exceptional artists.   The agency was borne out of their shared belief that artist representation in the UK can be revitalised to reflect the changing nature of the business.   The London-based partnership represent actors, comedians, presenters and writers across film, television and theatre. The three have come together from a variety of backgrounds: Duff was a director of Lou Coulson Associates where he had worked for 7 years, McCaughan had been at ICM for 6 years, and Rockcliffe was head of Talkback Management (a part of the Talkback Thames production company) for 11 years.