Updated

Shares in Kraft Heinz are expected to plunge when markets open Friday after the consumer goods company said it was being investigated by U.S. regulators and it reported a massive loss.

Kraft Heinz said it received a subpoena in October from the U.S. Securities and Exchange Commission related to an investigation of its procurement operations, which cover deals a company makes with outside suppliers. It said it's cooperating with authorities.

The probe was disclosed in the earnings report Thursday, in which it reported a massive $12.6 billion loss for the fourth quarter, compared with an $8 billion profit a year earlier.

The loss was largely due to a $15.4 billion writedown on the value of its Kraft and Oscar Mayer trademarks.

Shares were down 20 percent in premarket trading.