Three agencies were originally invited, OCBC Bank's head of group corporate communications Koh Ching Ching, has confirmed.
Koh added that the shortlisted agencies have been asked to provide costings for the scope of BTL work OCBC wants executed.
The BTL review is running parallel to the Singapore-based bank's ATL pitch, which sees incumbent Y&R defend the business in a final round of pitching with Euro RSCG.
Both reviews exclude digital, which is handled by a panel of agencies.
They are expected to be concluded by the end of August.