The move means that Mark Lund's role, as the group chief executive, will focus on managing the growth of the business in both advertising and non-advertising services, while Knox and Kuropatwa will take charge of the creative agency on a day-to-day basis.
The management of DLKW has remained constant since its buyout from True North four years ago.
Since then it has grown by more than 50 per cent in terms of income and headcount from a creative agency of 60 people. It has also expanded its non-advertising services with the growth of DLKW Dialogue from its roots in the digital arena into areas such as direct marketing and sales promotion.
Lund said: "Someone has to overlook the whole thing and it makes sense for me to do this."
Knox is one of the founding partners of the agency who took part in the management buyout - along with Greg Delaney, Mark Lund, Richard Warren, Malcolm Green and Gary Betts - from True North in 2000.
Kuropatwa started out as a graduate trainee at Delaney Fletcher Bozell.
He left the agency to join McKinsey & Co, before doing an MBA at Harvard. He eventually rejoined DLKW as the new- business director in January 2002.
For the past 18 months, he has combined overseeing new business with running account management.
The agency's line-up is completed with the arrival of Phil Edmonds from Leo Burnett as DLKW's new client services director. Along with overseeing account management, Edmonds will work on the agency's flagship Halifax business.
Greg Delaney, the chairman of DLKW, said: "As we grow, we want to continue to be as good as we have been up to now, if not better. Tom and Alex are extremely well qualified to help take us on to the next stage."
Lund said: "I couldn't wish to work with two brighter or more congenial companions than Alex and Tom."