Pile will be responsible for heading the agency's operations in London, Oxfordshire and the Midlands, and succeeds Bill Husselby, who will remain on the Cogent board.
The appointment marks Pile's return to advertising after a 17-year career in retail banking. He was previously the director of marketing services at Lloyds TSB and the business strategy and marketing director at Alliance & Leicester. Pile was the chief executive of Sainsbury's Bank from 1992 until earlier this year.
Pile started his career at D'Arcy Masius Benton & Bowles, moving to Dewe Rogerson in the late 80s as its managing director.
Husselby said: "Tim's appointment signifies a step-change in Cogent's development. His passion for, and commitment to, the Midlands as a centre of excellence for communications, combined with his outstanding experience and network, make him the perfect leader to take the agency forward."
Pile added: "The creativity and energy demonstrated by the team at Cogent makes me proud to be steering the agency through this next phase of growth. We will be re-energising the brand with additional offerings to reflect the changing marketing environment."