The statutory review includes media planning, buying and strategy for all of the body's advertising activity across TV, radio, press, outdoor, digital and ambient.
Media spend is dependent on the number of people involved in each switchover campaign and has been set between £18 and £26m by Digital UK to August 2012.
The appointed agency will work alongside Digital UK's existing retained non-media agencies Delaney Lund Knox Warren and Elvis, which are not affected by the review.
The contract will run for an initial two-year period, with the option of extending the contract for a further two years.
The media review comes ahead of an anticipated national campaign designed to promote the benefits of digital TV and encourage switchover before the 2012 deadline.
Most of Digital UK's budget is funded by the licence fee.
Earlier this year Digital UK moved its advertising account from Abbott Mead Vickers BBDO into DLKW following a competitive pitch process. Elvis was appointed to handle its direct marketing in February 2009 following a pitch which included the then incumbent, Rapier.
During the same year Grand Union retained the digital advertising account.
Established in 2005, Digital UK is the not-for-profit body formed at the request of the Government and Ofcom whose shareholders include the BBC, ITV, Channel 4, Five and S4C, and transmission companies SDN and Arqiva.
The company completed its first digital switchover in Whitehaven, Cumbria, in 2007 and has since completed the Scottish Borders, the West Country, the North West, Wales and the West regions.
The UK's entire switchover programme is expected to finish in Northern Ireland in 2012.