The agency has been brought on board for the company's Goldsmiths, Mappin & Webb, Watches of Switzerland and mydiamonds.com accounts.
The agency was awarded the brief following a three-way pitch. The account is believed to be worth six figures and will be headed by Biss Lancaster associate director of luxury and lifestyle brands Melanie Charlesworth.
The account will be led from the agency's London office, which will be working with Aurum on a national strategy that aims to develop and establish 'emotional ties' between the brands and consumers.
The agency's Manchester office will focus on regional PR and marketing support.
Biss Lancaster is charged with handling national, regional and online media relations activity for the brands, as well as providing events and marketing support. The agency will also support the launch of mydiamonds.com.
'We will be targeting consumers of luxury brands and the media they consume and experience,' said Charlesworth.
Aurum Holdings announced its first-quarter results last month. Group like-for-like sales rose by 10.7 per cent in conjunction with an improvement in profits over last year. The firm reported a pre-tax loss of £14.2m in the 12 months to January 2007.