Westlake (WLK) reported a Q4 adjusted loss Tuesday of $0.25 per diluted share, swinging from earnings of $0.06 a year earlier.
Analysts polled by FactSet expected a non-GAAP loss of $1.41 per share.
Net sales for the quarter ended Dec. 31 were $2.53 billion, down from $2.84 billion a year earlier.
Analysts surveyed by FactSet expected $2.60 billion.
Shares of Westlake were up more than 2% in recent premarket activity Tuesday.