Two agencies are believed to be in contention for the business after the split between BHO and the Chewits manufacturer, Leaf UK.
Sven Olsen, the managing director of BHO, confirmed they had parted company at the end of last year.
The brand's last significant spend was in 2001 with a TV campaign featuring Chewie the Chewitsaurus and the strapline: "Chew Chewits coz Chewits do it."
The advertising, which was aimed at five- to 11-year-olds, will continue to run on GMTV and children's satellite channels, after Leaf and BHO managed to reach an agreement over assignment of copyright.
Leaf, which is owned by the Dutch-based CSM group, Europe's second-largest sugar confectionery manufacturer, claims that the Chewits brand is performing well in what has been an otherwise generally depressed UK confectionery market. It achieved a 5.7 per cent year-on-year increase in value sales.
However, the children's confectionery market has to be driven by constant new product launches and last year Leaf extended the Chewits brand to include a jelly sweets range.
"The problem Leaf has with the Chewits brand is that although new flavour launches increase revenue, they can become difficult to manage," an industry source said. "Now Leaf is rationalising its range and regrouping."
Advertising support for the brand had been around £600,000 but this adspend dwindled to almost nothing last year.