Takeda, Japan's largest drugs firm by sales, has said it is considering a possible offer for the UK's Shire.

The Takeda announcement sent shares in the UK pharmaceuticals company up as much as 25% in morning trading.

Big drugs names have long been rumoured to have been circling Shire after a takeover by US firm Abbvie fell through in 2014.

In mid-December last year, speculation on a possible takeover bid sent Shire shares to the top of the FTSE 100.

Takeda said its offer "is at a preliminary and exploratory stage and no approach has been made to the board of Shire".

However, Takeda said it was interested in the firm to strengthen its cancer, stomach and brain drugs offerings.

Takeda must announce that it intends to make a firm offer for Shire by the end of 25 April.

Bigger picture

CMC Markets analyst Michael Hewson said the interest in Shire "is part of a wider story" in the pharmaceutical industry.

He said plans by Amazon, investor Warren Buffett and JPMorgan Chase to create a company to provide employees with affordable healthcare had helped prompt further consolidation in the pharmaceutical sector.

Shire is incorporated in Jersey, and has its headquarters in Dublin. However, most of its 24,000 employees are located in the US.

It was started in 1986 by a small group of entrepreneurs who started selling calcium treatments for osteoporosis.

Two years ago Shire bought Baxalta, a specialist in treatments for rare diseases, for $32bn.

Japan's Takeda was founded in 1781 and employs 30,000 people. It operates in more than 70 countries.