Cadbury’s shares fell to their lowest level since Kraft publicly revealed its indicative takeover offer two months ago as analysts cut estimates of how much the US food group is likely to offer in a formal bid.

Under Takeover Panel rules, Kraft has until Monday to make a formal bid for Cadbury and improve its indicative cash and stock offer, which on Wednesday was worth £9.8bn ($16.2bn), or 719p per Cadbury share.