X0306 4 2018-01-10 0 0001333274 MERCER INTERNATIONAL INC. MERC 0001258686 GANDOSSI DAVID M SUITE 1120 700 WEST PENDER STREET VANCOUVER A1 V6C 1G8 BRITISH COLUMBIA, CANADA 1 1 0 0 Chief Executive Officer Common Stock 2018-01-10 4 S 0 12000 14.1948 D 175714 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 10, 2017. The price reported in Column 4 is a weighted average price. The common stock was sold at prices ranging from $14.10 to $14.35. Upon request, the Reporting Person will provide to the Securities and Exchange Commission staff, the Issuer and any security holder of the Issuer full information regarding the number of shares of common stock sold at each separate price within the range. /s/ David Gandossi 2018-01-10