Dresdner Kleinwort Wasserstein is backing UK buy-out firm Candover in its bid to buy Alcontrol, a laboratory testing services group, from rival buy-out firm Bridgepoint Capital.

Dresdner is lead arranger for the debt for the £250m (€357m) deal and Bank of Scotland, part of the Scottish banking group HBOS, may become involved as a co-underwriter, according to a source close to the deal.