Initiative, which handles media for General Motors' Vauxhall cars in the UK, won the Daewoo account after GM bought the Korean car company earlier this month.
The media account was previously held by Mediaedge: cia. Before Media Edge and CIA merged, it was held by CIA, which won the business in 1994 ahead of Daewoo's UK launch.
The appointment of Initiative comes after last week's selection of DFGW to handle Daewoo's £40 million pan-European creative task. The agency, which was hired by Daewoo for its UK launch and developed the strapline "That'll be the Daewoo", will work alongside the Publicis-backed European network Buehler & Partners.
DFGW will also continue to handle Daewoo's UK creative account, which is run separately from the European brief. Earlier this year Daewoo began a review of the UK creative account but abandoned the pitch.
Daewoo's media spend is skewed toward press, with a small amount of TV and cinema activity. It has spent heavily on its Matiz model and has also backed its Tacuma and Lanos cars with press spend.
Earlier this month Daewoo UK was placed into administration because the original deal between GM and Daewoo did not include the UK operations of Daewoo. Since then, however, GM has said that it will take on customer service agreements with existing Daewoo customers and the future UK marketing.