The US bank is expected to explore the possibility of putting parts of its MBNA media business into PHD or its Omnicom stablemate OMD. The bank is said by one source to have started discussions with Omnicom networks.
It is unclear whether this will lead to changes in the UK.
In the UK, MBNA's £10 million media spend is planned and bought by Zed Media. Online media is handled by BLM Quantum, which was appointed to the £9 million account in February after a lengthy pitch process handled by Billetts.
The bulk of Bank of America's activity is consolidated into Omnicom agencies.
OMD handles its US media planning and buying while the BBDO network handles creative. Abbott Mead Vickers BBDO was appointed as MBNA's UK creative agency at the same time as BLM Quantum won the online media business.
MBNA's appointment of BLM Quantum as its digital specialist is part of a UK strategy to recruit more customers online.