UPDATE 1-Japan's Takeda considering approach for British drugmaker Shire

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LONDON, March 28 (Reuters) - Japan's largest drugmaker Takeda Pharmaceutical said it was considering a possible bid for Shire to help expand its presence in the United States, sending shares in the British pharmaceuticals company up as much as 25 percent.

Takeda said its approach for the owner of rare disease and hyperactivity drugs was "at a preliminary and exploratory stage and no approach has been made to the board of Shire".

It said a deal would create a global biopharmaceutical leader and strengthen its presence in the treatment of rare diseases and the oncology, gastrointestinal and neuroscience sectors.

It said it would also balance Takeda's geographic focus to align with the market opportunity in the United States.

Shares in Shire have been weak for the last year after the group said earnings would be held back by greater competition from generic drugs and lower royalties. As of 0950 GMT, Shire had a market valuation of around 32.7 billion pounds ($46.3 billion).

It has announced a plan to split its business in two, dividing the rare disease and hyperactivity medicines businesses to boost performance. ($1 = 0.7061 pounds) (Reporting by Rahul B in Bengaluru and Kate Holton in London Editing by Louise Heavens and Keith Weir)