The retailer's marketing director David Roth has held talks with top London ad agencies, including WPP's J Walter Thompson, about the account.
Roth is keen to avoid any disruption to his business if the incumbent, Bates UK, is not able to continue handling the account because of financial difficulties afflicting Cordiant.
B&Q ranks at number 35 in the top 100 UK advertisers, according to Nielsen Media Research. Bates has held the account for nearly 20 years and its TV ads consistently top Marketing's Adwatch chart.
Although Roth remains happy with Bates' performance on the creative account, which has seen B&Q engaged in a fierce price war with DIY rival Homebase, sources said he has been making contingency plans.
It is thought Roth would move the business to another agency on the condition that it employs the team that currently works on the account at Bates.
Roth, who was unavailable for comment, is understood to be less concerned about the tenure of B&Q's media buying account because it is currently held by ZenithOptimedia, in which Cordiant holds only a 25% stake.
A defection by B&Q, one of Bates' biggest remaining UK clients, would be another blow, after the departure of key accounts such as Woolworths and Royal Mail in the past few months. Other major clients, including Sky, are understood to be considering their options, while the Wella business may be realigned as a result of the company's acquisition by Procter & Gamble.
A number of prospective buyers have emerged in the past few weeks, with Publicis Groupe among the candidates reported to be interested in some parts of the company. Publicis owns the remaining 75% of ZenithOptimedia.
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