AMERICAN drugs firm AbbVie has reconsidered its £32billion takeover of Basingstoke-based rival Shire after the US Treasury announced new tax rules.

In light of the new regulations the North Chicago-based company’s board is recommending its shareholders vote against the deal because of new tax changes give an "unacceptable level of uncertainty."

Rules unveiled in September aim to crack down on American businesses moving their headquarters overseas to avoid US taxes.

When the proposed merger was announced in July the two drug manufacturers had planned to base the new company’s headquarters in Jersey, in The Channel Islands.

In a statement, Richard Gonzalez, AbbVie's chairman and chief executive, said: “The agreed upon valuation is no longer supported as a result of the changes to the tax rules and we did not believe it was in the best interests of our stockholders to proceed."

Shire, based on Hampshire International Business Park, said AbbVie will have to pay a break fee, which could be as much as £1billion if the company walks away from the deal.

The FTSE 100 company, which is also listed on, New York’s NASDAQ and the Toronto Stock Exchange has large operations in America.

Shire, which is primarily known for making drugs to treat rare diseases and employs around 400 people in Basingstoke.

AbbVie is a specialist in treating arthritis.