The agency is said to have seen off competition from DFGW and Fallon to win a slice of BT's £95 million advertising account, joining Abbott Mead Vickers BBDO and St Luke's on its roster. However, a formal appointment is not expected until next week.
CHI's relationship with Carphone Warehouse, which is launching a residential phone service called Talk Talk, preceeded the pitch and is not expected to deter the appointment.
However, the agency may be more likely to face conflict issues in the forthcoming pitch for British Gas, as the utility company has a telecoms arm called British Gas Communications.
Its first task as BT's third agency would be to create a campaign to promote the Bluebox broadband phone boxes.
A place on the roster would give CHI opportunities to work on large BT projects. Last year, AMV was handed the £10 million creative account to market its 118500 directory enquiries service.
The pitch, which was handled by the AAR, was called at the end of last year.
The decision to appoint CHI follows a busy few months of reviewing for BT. Last month, it appointed WWAV Rapp Collins to handle its £4 million business direct marketing account. And in November 2002, it awarded its £23 million press implementational planning and buying account to the Starcom MediaVest Group.
BT also refined its digital creative agency roster late last year in a bid to bring about a more integrated online marketing strategy. It expanded Agency Republic's remit, handed Agency.com the business advertising account and gave Oyster Partners sole responsibility for web design and development.
Johnnie Hornby, CHI's managing partner, refused to comment on the appointment.