Twin Rivers Paper Co. will lay off 49 workers at its Madawaska paper mill, shutting down one paper machine while reconfiguring another to produce a different grade of paper.

The company said the machine it is shutting down is one of its oldest and costliest. It produces a variety of coated and uncoated grades of paper.

At the same time, the company said it will invest $12 million in another machine at the mill to produce lightweight technical specialty paper. The company said the moves will result in a more productive mill, which employs about 500 workers.

The reconfiguring of the machine will be completed in 2017, the company said.

The company did not say when the layoffs will take place and whether workers will be eligible for severance pay or help finding a new job. A call seeking more information was not immediately returned.

Verso Corp., which operates a paper mill in Jay, said Monday that it will seek to change its product mix to more profitable grades of paper as it emerges from bankruptcy. The company has historically made coated paper for publishing clients, but is interested in making more specialty papers, which are often used for labels, packaging and other niche products.

Last month, Catalyst Paper, which operates a mill in Rumford, restarted an idled machine to produce a new grade of specialty paper. Rumford Offset is an uncoated specialty paper, intended to be used in marketing materials.

This story was changed from its original version to correct the description of Rumford Offset paper.