Last month M&C Saatchi received a buyout offer from AdvancedAdvT, led by one of the agency’s independent board directors Vin Murria.
The agency rejected the initial offer and a follow-up proposal that an evaluation committee concluded undervalued the firm.
But negotiations are continuing, an indication that both sides still see room to complete a deal.
At the request of both sides, the UK regulatory body that oversees M&A transactions has extended until March 3 a deadline by which Advanced has to make a firm offer commitment or declare its intention not to.
But talks could go on longer if both sides see progress and ask for another extension.