ADK announced last week ( 2 October) that it supported the tender offer from Bain Capital, worth $1.3bn. WPP owns a 24.7% stake in ADK.

In the statement, WPP said that the tender offer "significantly undervalues ADK", adding that this is a view stated "both publicly and privately" by other shareholders. 

The statement also cast blame on ADK’s management and accused the company of attempting to "improperly" terminate the business agreement with WPP.

It said: "ADK’s management have consistently resisted opportunities to improve the performance of its overseas operations and exploration of significant digital opportunities, preferring to invest in disastrous acquisitions and consolidations such as Gonzo and Bungeisha, the costs of which have not been fully exposed, along with the disposal of DAC in 2011 at a lower price than WPP’s indication and the reduction of ADK’s stake in Video Research Interactive.

"ADK has improperly attempted to terminate its co-operation and business alliance agreement with WPP, which it knows full well that it cannot do, as on previous occasions it had abided with this instruction.

"ADK’s effective sale of its holding in WPP has attempted to circumvent the stock purchase agreement and contradicts explicit advice from key shareholders that doing so would trigger damaging and ill-advised tax charges."