Shares of Domtar Inc. UFS, -4.88% slid 2.6% in premarket trade Friday, after the maker of fiber-based products warned that fourth-quarter results fell short of expectations. The Fort Mill, South Carolina-based company, which makes products used in packaging and absorbent hygiene products, said it now expects fourth-quarter sales of $1.2 billion, compared with a $1.3 billion FactSet consensus. It expects an operating loss of $15 million to $19 million, that includes closure and restructuring costs of about $19 million and depreciation and amortization costs of $74 million. “We increased market-related downtime to better balance our supply with our customer demand and to accelerate our inventory reduction plan,” Chief Executive John D. Williams said in a statement. “Our inventories are now at optimal levels and our expectation is that our business will return to a balanced level in early 2020 given recent capacity closures.” The company expects to post its fourth-quarter earnings on Feb. 7 before the market open. Shares have fallen 11.6% in the last 12 months, while the S&P 500 SPX, -0.90% has gained 26%.