Takeda Pharmaceutical Co. is considering selling its symbolic Osaka headquarters building to help finance its £46 billion ($60 billion) deal to acquire Irish drugmaker Shire Plc., sources close to the matter said Friday.

The building, located in the Doshomachi district in the city of Osaka, stands on the same site where the company was founded in 1781. While Takeda has moved its headquarters functions to its Tokyo office, the building in Doshomachi — historically known as a center for medicine — is registered as its official headquarters.

Takeda is expected to raise tens of billions of yen through the sale of the building in an effort to bolster its finances and quell criticism from some of its shareholders that the Shire deal is too costly.

The purchase of London-listed Shire amounts to the biggest-ever Japanese acquisition of a foreign company.

Takeda is aiming to win shareholder approval in early 2019 for an issue of new shares to finance the acquisition, and close the deal by next June.

Among other efforts to streamline its businesses, Takeda sold last year its roughly 70 percent stake in its chemical research unit Wako Pure Chemical Industries Ltd. to Fujifilm Holdings Corp. for about ¥155 billion.

It has also decided to sell properties, including a former Tokyo headquarters building in the capital's Chuo Ward, to department store operator Takashimaya Co. for about ¥50 billion.