First mooted in December last year, the acquisition of the combined €900m (£784m) turnover companies was finally completed on 13 July 2011.
UPM issued 5m new shares at €10.84 per share to direct and indirect owners of its new businesses and drew €800m in long-term debt in order to finance the deal.
The deal includes seven publication paper mills in Germany, Finland and the United States, which produce 2.8m tonnes of paper per year.
UPM will report a one-off gain of approximately €40m in the third quarter of 2011, while the company has also stated that its earnings per share will be "positively impacted" from 2012.
The company said that annualised cost savings of around €100m could be achieved when the businesses were integrated.
UPM president and chief executive Jussi Pesonen said: "Consolidation and restructuring are the best way to make fundamental improvements in terms of cost efficiency and to create value in the paper business."
Jyrki Ovaska, president of UPM's Paper Business Group added: "The planning work to identify cost synergies is still ongoing. As the transaction is now completed, we have access to detailed information on Myllykoski operations and business units and we can verify the various options.
"UPM has strong confidence in the print industry and our target is to be a very competitive paper supplier. After the transaction, we will be better able to meet customers' needs with an extended product portfolio and strong local presence."
