The potential clashes are with CHI's founding client, Carphone Warehouse, and British Gas, whose account the agency is pitching for.
Carphone Warehouse aims to undercut BT in the residential phone market with its Talk Talk service, while British Gas has its own telecoms arm, British Gas Communications.
CHI is understood to have won the pitch, organised through the AAR, against Fallon and DFWG. CHI was unavailable for comment. BT Retail director of marketing services Amanda MacKenzie said it would not make a decision until the end of the week.
A third agency would take a slice of BT's £96.5m ad account alongside St Luke's and Abbott Mead Vickers BBDO. It will initially create ads to attract consumers to BT's Bluebox broadband phone boxes.
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