X0306 4/A 2020-02-13 2020-02-14 0 0001333274 MERCER INTERNATIONAL INC. MERC 0001080730 LEE JIMMY S H SUITE 1120 700 WEST PENDER STREET VANCOUVER A1 V6C 1G8 BRITISH COLUMBIA, CANADA 1 1 0 0 Executive Chairman Common Stock 2020-02-13 4 M 0 31932 0 A 1866630 D Performance Share Units 0 2020-02-13 4 A 0 31932 0 A Common Stock 31932 31932 D Performance Share Units 0 2020-02-13 4 M 0 31932 0 D Common Stock 31932 0 D Represents the conversion of vested performance share units ("PSUs"). Represents the vesting on February 12, 2020 of PSUs awarded to the reporting person based on the achievement of certain specified performance criteria, including company performance, share price performance and individual performance during the 2017 to 2019 performance period. This amendment to the Form 4 originally filed on the same date is being filed solely to indicate the reporting person is also a director of the issuer. No other information is being amended. /s/ Jimmy Lee 2020-02-13