The creation of openreach, which will house BT's 25,000 engineers but be separate from the retail business, is part of the settlement reached with industry regulator Ofcom.
A multimillion-pound ad campaign is expected to launch the division, which will work for both BT and its rivals. Industry observers believe it is highly unlikely BT would be allowed to appoint a roster agency to develop the campaign.
An Ofcom spokesman confirmed BT had under-taken to ensure 'operational separation' and this would include the division's marketing function.
However, BT said it was too early to comment on marketing plans for the division.