The agency won the brief following a competitive pitch, and will be expected to design the new Zavvi brand by mid November. Zavvi Entertainment Group, which was formed by Virgin Megastores' management team, wants an identity that "reflects the pride and passion of the company".
The work involves a redesign of 125 Virgin Megastores across the UK and Ireland.
Colum Lowe, Caulder Moore managing director, said: "We're really excited about this opportunity as it's not every day you get appointed to assist one of Britain's top retailers in the development of their brand, the results of which will be highly visible to all on every major high street in the UK."
Sir Richard Branson's Virgin Group made the decision to sell Virgin Megastores, which was founded in 1977, having undergone heavy losses in recent years following an increasing price squeeze from online retailers.
Zawi Entertainment is a management buyout group led by Virgin Megastores managing director Simon Douglas and its finance director Steve Peckham.
Cathy Kebbeh, head of branding and advertising at Zavvi, said: "[Caulder Moore's] extensive experience of the commercial realities of rebranding large, national retailers will be vital in helping us to communicate the new brand's authority as the leading independent entertainment specialist."