US drug firm AbbVie has clinched a deal to buy the UK pharmaceutical company Shire for £32bn.

On Monday 14th July, U.S. drugmaker AbbVie has announced plans to takeover Dublin-based pharmaceutical company Shire in a deal worth around £31 billion ($53 billion), as AbbVie seeks to lower its tax rate by buying a foreign rival.

The Shire board has backed an offer that will be made up of £24.44 in cash and 0.8960 AbbVie share per Shire share, meaning AbbVie will pay about £52.48 per share for the specialist pharmaceutical firm. Shire shareholders will end up owning 25 percent of the new merged group. AbbVie said it expects the deal will cut its effective tax rate to approximately 13 percent. Shire shares were up as much as 2.5 percent shortly after the deal was announced.

If the takeover is successful, North Chicago-based AbbVie plans to relocate the new combined firm in the U.K., allowing it to benefit from the country's lower tax. It is but the latest example in a flurry of acquisitions known as inversions. In an inversion, a large U.S. firm acquires a much smaller target company domiciled in a tax-friendly jurisdiction such as Ireland or the U.K., but the deal is structured so that the foreign minnow swallows the domestic whale. U.S. shareholders of the U.S. firm must pay immediate capital gains tax for the privilege of inversion, and the U.S. company ends up as the nominal subsidiary of a publicly held foreign corporation.

 Shire is the second FTSE-listed pharmaceutical firm that has been approached by a U.S. rival, after Pfizer's failed takeover bid for U.K. group Astra Zeneca. The Shire Board, has been advised by Citi, Deutsche Bank, Evercore, Goldman Sachs and Morgan Stanley. Shire said the banks consider the terms of the transaction to be fair and reasonable.