MINNEAPOLIS (AP) - General Mills is buying Blue Buffalo Pet Products Inc. in a deal valued at about $8 billion.

General Mills Inc. will pay $40 per Blue Buffalo share. That's a 17 percent premium to the pet food company's Thursday closing price of $34.12.

Shares of Blue Buffalo surged more than 5 percent in Friday premarket trading.

Blue Buffalo makes natural foods and treats for dogs and cats. Its Blue brand had approximately $1.28 billion in net sales in fiscal 2017.

Minneapolis-based General Mills said once the transaction closes, Blue Buffalo will be run as a new pet operating segment.

Blue Buffalo is expected to keep its Wilton, Connecticut headquarters.

The deal is targeted to close by the end of General Mills' fiscal year 2018.