LONDON (Reuters) - Japan's Takeda Pharmaceutical 4502.T will hold an investor vote on its $62 billion acquisition of Shire SHP.L next month and aims to close the deal on Jan. 8, signaling its confidence in securing the required support.

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Shares in London-listed Shire rose 3 percent on the news, hitting their highest level since Takeda first disclosed its interest in buying the rare diseases specialist in March.

The deal would be the biggest-ever overseas acquisition by a Japanese company - but it needs two-thirds support from shareholders, some of whom are worried about the enlarged company’s resulting debt burden.

Takeda said on Monday it would hold an extraordinary general meeting (EGM) of shareholders to vote on the transaction on Dec. 5.

Previously, Takeda had said it hoped to hold the EGM early in 2019, leaving uncertain the level of backing for the deal, which has been opposed by some members of the founding Takeda family.

“With the date of our extraordinary general meeting of shareholders now set, we are looking forward to continue our dialogue with shareholders regarding the compelling strategic and financial benefits of this transaction,” Chief Executive Christophe Weber said.

Weber -- a Frenchman and the first non-Japanese CEO of the company -- believes that buying Shire will accelerate Takeda’s growth and increase its international reach, boosting earnings.

The transaction is still awaiting approval from European regulators, although two people familiar with the matter told Reuters last week that Takeda was set to win conditional EU antitrust approval.

Takeda has offered to divest Shire’s experimental drug SHP647 to address concerns about overlap in inflammatory bowel disease treatments.

The takeover has already secured clearance from regulators in the United States, Japan, China and Brazil.

Weber said last week he was confident of securing investor backing for the purchase of Shire, but until now it has not been clear when exactly Takeda would call its EGM.

Takeda, which has a market value of around $32 billion, has secured a $30.9 billion bridge loan to help finance the Shire acquisition and some investors are concerned as to how well it will cope with debt repayments.

The Japanese company struck its agreement to take over Shire in May, in a deal that will propel it into the top 10 rankings of global drugmakers by sales.

However, the enlarged group faces significant challenges, particularly in hemophilia, where a new drug from Roche ROG.S and the prospect of new gene therapies now in development threaten a key part of Shire's existing business.