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.

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