TOKYO (AP) — Japanese drugmaker Takeda has agreed to buy Ireland-based Shire for 46 billion pounds ($62.4 billion) in one of the biggest pharma deals to date.

The companies said in a statement Tuesday that Takeda agreed to pay the equivalent of 49.01 pounds in cash and stock for each share of Shire, based on Shire's closing price on April 23, when the tentative offer was made.

Shire focuses on rare diseases, a field of increasing interest to pharmaceutical companies facing growing competition from generic drugs as patents on their established medicines expire.

Shire's headquarters are Dublin but it has large operations in the U.S., where it earns more than two thirds of its revenue.

Shire says its shareholders would own about 50 percent of the merged company.