Altria Group Inc. again slashed the value of its investment in Juul Labs Inc. and stripped down its agreement to provide services to the startup as it weathers mounting scrutiny of the e-cigarette market.

The tobacco giant on Thursday said the value of its stake in Juul fell by $4.1 billion in the fourth quarter. It now values the e-cigarette maker at about $12 billion, down from its $38 billion valuation when Altria invested in December 2018.

It is the second big charge the Marlboro maker has taken on its controversial investment. In October, Altria wrote down its Juul stake by $4.5 billion. The company said the latest charge reflected mounting litigation against Juul.

“I’m highly disappointed in the performance of our Juul investment,” said Altria Chief Executive Howard Willard. He cited a number of surprises, including a vaping-related lung illness that prompted U.S. health officials to warn consumers last year not to use e-cigarettes before they determined the illnesses were linked not to e-cigarettes but to vaping devices containing marijuana extracts and vitamin E oil.

Facing an accelerating decline in cigarette sales, Altria in 2018 paid $12.8 billion cash for a 35% stake in Juul, making it one of Silicon Valley’s most valuable startups.