MOSINEE, Wis. – Wausau Paper Corp. has sold a portion of its business and will close facilities in Columbus, Wis., and Jackson, Miss., next year, cutting 57 jobs.

The Mosinee-based company said in a Securities and Exchange filing that it has sold its roll wrap business to paper and packaging maker Cascades Sonoco Inc. Terms of the deal were not disclosed.

The sale means the company will shut down the two plants, one in Wisconsin, where 45 people work, and one in Mississippi, where 12 people work.

Company spokesman Perry Grueber said Wausau Paper will run the two plants until July and then close them. The buyer will not operate the plants, he said.

Wausau Paper had told the state of Wisconsin in a regulatory filing that the first layoffs would come within two months.

The roll wrap business is part of Wausau Paper’s specialty products segment. Moisture-barrier laminated roll wrap is used to protect paper in storage and shipment, among other products. It represents about 3 percent of Wausau Paper’s annual revenue, which hit $1.2 billion in the 2006 fiscal year.

The move follows Wausau Paper’s announcement in October that it would close its mill in Groveton, N.H., by the end of the year, leaving 300 people without jobs.

Its Canadian competitor, Domtar, announced last week it was closing a paper mill in Port Edwards, Wis., cutting 500 jobs.