UPDATE 2-Japan's Otsuka eyes $12 bln Dec listing -sources

* Drugmaker will list on Tokyo Stock Exchange after IPO

* Market value may be $12 bln, earn top 5 Japan sector rank

* IPO could be among largest in Japan in recent memory

(Adds details, background)

By Ritsuko Shimizu and Taro Fuse

TOKYO, Oct 29 (Reuters) - Drug and food firm Otsuka Holdings plans to list its shares in Tokyo in early December after what will likely be one of the largest initial public offerings in Japan this year, two sources familiar with the matter said.

Otsuka Pharmaceutical, the biggest unit of the holding firm, has developed schizophrenia drug Abilify and teamed up with Bristol-Myers Squibb BMY.N to sell it in the U.S. and some other markets.

The company, which also sells sports drinks, instant meals and skincare products, held a special meeting of shareholders on Friday and gained approval to change its corporate charter to allow for a stock exchange listing, the sources said.

The sources spoke on condition of anonymity because they were not authorised to comment to media on the deal.

An Otsuka spokesman confirmed a shareholders’ meeting was held and the charter was altered, but gave no other details.

Otsuka planned to list on the Tokyo Stock Exchange this summer, valuing the whole company at some 1 trillion yen ($12.3 billion), Reuters reported in January. [ID:nTOE60R05F]

A market capitalisation of that size would place it behind only three other drugmakers in Japan -- Takeda Pharmaceutical 4502.T, Astellas Pharma 4503.T and Daiichi Sankyo 4568.T -- and roughly on a par with Eisai Co 4523.T.

Otsuka’s listing could also rank as one of the largest in Japan in recent memory.

Japan's IPO market has been in the doldrums with the exception of Dai-ichi Life Insurance Co's 8750.T $11 billion listing in April.

Otsuka booked an operating profit of 98.5 billion yen in the financial year ended March 2010, on sales of 1.08 trillion yen.

($1=81.03 Yen)