The telecoms giant has short-listed Starcom Digital, Zed Media, MOne and one unknown agency for the account.
A consortium of The Allmond Partnership and digital specialist Profero were eliminated from a longlist of agencies. Unique Digital was also asked to pitch but declined.
A decision is expected mid-June with the winning agency taking over the account from i-level in July.
If mOne scooped the business it would align the company with its sister agencies OgilvyOne and Ogilvy Interactive, which are on BT's creative roster.
Similarly, Starcom UK handle media buying for BT's main accounts and online, so a tie-in with Starcom Digital may be favoured.
I-level, the biggest dedicated online media agency in the UK, held the BT account for five years but resigned it in April after winning the £8m digital planning and buying business for Orange from Initiative.
The pitch comes as earlier this week BT reported a 44% jump in profits to £435m in the last quarter of the fiscal year on the back of broadband internet uptake.
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