FTSE 100-listed Shire said that it had received a fifth takeover proposal from Takeda on Tuesday but did not give details of the revised bid. It said its board was considering its position.
It comes after Takeda’s fourth bid for Shire on Friday, which was pitched at 47 pounds per share and comprised 26 pounds in Takeda stock and 21 pounds in cash. That valued Dublin-based Shire at 44.3 billion pounds.
Under British rules, Takeda has until 5 p.m. on Wednesday to make a firm offer or walk away from Shire.
However, that deadline can be moved back at the request of the FTSE 100 drugmaker and Takeda had said on Friday that it hoped negotiations with Shire would lead to an extension of the cut-off date.
Shares in the London-listed company were up 5.3 percent at 40 pounds in afternoon trade.
The latest bid comes as Shire prepares to hold its annual shareholder meeting in Dublin at 2.45 p.m. local time, when it is expected to be grilled by its investors about the potential acquisition by Takeda.
Shire focuses on drugs to treat rare diseases and attention deficit hyperactivity disorder and a takeover would catapult Takeda into the top ranks of global drugmakers.
It would also mark the biggest ever overseas acquisition by a Japanese firm.