The world's largest magazine paper maker UPM-Kymmene said on Thursday it would buy all outstanding shares in an Estonian mill for an undisclosed sum to bolster its leading position in the European plywood market. UPM-Kymmene said in statement it will purchase shareholdings in AS FSS Plywood from Stora Enso Timber AS, an Estonian unit of Finnish-Swedish Stora Enso, and AS Forestex. As part of the deal, UPM will sell its 34 percent holding in AS Forestex to Stora Enso Timber AS for an undisclosed sum. UPM-Kymmene previously held an about 40 percent stake in AS FSS Plywood, mid-sized saw mill with an annual output capacity of 20,000 cubic metres, a UPM official told Reuters. "We are already the biggest producer of plywood in Europe and in that sense it is clearly our business area and we wish to strengthen our position in Estonia," Kari Makkonen, the president of UPM-Kymmene's wood products unit, told Reuters. UPM-Kymmene said the deal was subject to approval by competition authorities.