Shire: AbbVie should proceed with $55 billion combination of the 2 drugmakers

The drugmaker Shire wants AbbVie to stick with its roughly $55 billion acquisition bid, and it is reminding its U.S. counterpart of the hefty breakup fee it will receive if things don't work out.

Shire's shares lost nearly a quarter of their value in premarket trading the morning after AbbVie Inc. disclosed its cold feet on the deal.

Shire said Wednesday its board believes AbbVie should follow through with its plan to acquire Shire and reincorporate on the British island of Jersey, where Shire is incorporated.

The U.S. government created new limitations last month on the tax benefits of incorporating overseas.

Shire had rejected several unsolicited offers from AbbVie before the companies made the deal in July. Shire says it could be entitled to a breakup fee of $1.64 billion.