The site and its assets will be sold to US-based uncoated paper producer Sylvamo for €150m ($149.7m).
The deal is subject to regulatory approvals and expected to close at the beginning of next year.
Stora Enso’s Nymölla site houses two pulp lines and manufactures 485,000t of woodfree uncoated office papers, serving a number of brands, including Multicopy.
For the 52 weeks to 30 June, the integrated facility recorded €350m in revenue.
The divestiture is part of Stora Enso’s previously announced plan to divest four of its five paper production sites.
The company expects a reduction of around €290m in its annual sales due to the sale.
Stora Enso paper division CFO Seppo Parvi said: “Following our recent agreement to divest the Maxau site, I am pleased that we found a good, experienced owner in Sylvamo for our Nymölla site.
“The process to divest the remaining paper assets continues.”
Following the deal, Sylvamo plans to integrate the Nymölla site into its global paper business.
The mill will complement the company’s efforts to produce paper using sustainable processes, as it meets 85% of its energy requirements through carbon-neutral, renewable biomass residuals.
In addition, Sylvamo will retain all 520 of the employees at the Nymölla mill.
Sylvamo chairman and CEO Jean-Michel Ribiéras said: “We expect this acquisition to strengthen our uncoated freesheet product mix, enable us to serve customers across Europe and around the world more effectively and be immediately accretive to our earnings per share and free cash flow.”