The pitch, which was run through the AAR, saw an initial shortlist of six creative houses, including Farm, which was then clipped to four.
The Chrysalis Group plans to drive the profile of the talk station to appeal to a younger demographic as it shifts LBC from the AM frequency to 97.3FM. It currently targets over-35s.
As part of the move to freshen up the brand's image, Caroline Feraday, who presents The Weekend News with Matthew Bannister on BBC Radio Five Live, will join the on-air team, after turning down an offer from Capital Radio to co-host Chris Tarrant's breakfast show.
A media schedule has yet to be finalised, but it is believed that Chrysalis Radio plans to use a cross-media approach, including TV, press, radio and new media executions.
Rajar data for the third quarter this year showed a 33 per cent leap in listeners to LBC to 480,000.
Chrysalis acquired LBC's owner, London News Radio, from a consortium of ITV, Reuters, DMGT and GWR for £23.5 million.