X0609 4 2026-06-01 0 0001333274 MERCER INTERNATIONAL INC. MERC 0000897485 KELLOGG PETER R false 48 WALL STREET C/O IAT INSURANCE CO. LTD NEW YORK NY 10005 0 0 1 0 0 Common Stock 2026-06-01 4 P 0 16000 0.8984 A 981929 D Common Stock 2026-06-01 4 P 0 36000 0.8992 A 1017929 D Common Stock 2026-06-01 4 P 0 2731 0.8987 A 1020660 D Common Stock 2026-06-01 4 P 0 10154 0.9094 A 1030814 D Common Stock 2026-06-02 4 P 0 1047 0.9155 A 1031861 D Common Stock 2026-06-04 4 P 0 36000 0.8894 A 1067861 D Common Stock 2026-06-05 4 P 0 36000 0.8498 A 1103861 D Common Stock 2026-06-08 4 P 0 34733 0.7984 A 1138594 D Common Stock 2026-06-09 4 P 0 23637 0.7938 A 1162231 D Common Stock 2026-06-10 4 P 0 36000 0.8243 A 1198231 D Common Stock 2026-06-11 4 P 0 136000 0.8599 A 1334231 D Common Stock 2026-06-12 4 P 0 36000 0.9306 A 1370231 D Common Stock 2026-06-12 4 P 0 1210 0.9047 A 1371441 D Common Stock 2026-06-12 4 P 0 200 0.9085 A 1371641 D Common Stock 2026-06-12 4 P 0 14031 0.91 A 1385672 D Common Stock 1957000 I Via Harco Common Stock 253000 I Via E.G. Anderson Inc. Common Stock 1000000 I Via Peter and Cynthia Kellogg Foundation Common Stock 1360000 I Via Non Marital PRK Trust Common Stock 2300000 I Via Spouse Common Stock 2000000 I Via Bermuda Partners Common Stock 10000 I Via Cardia Company Inc. Common Stock 13475000 I Via IAT Insurance Co. Ltd. Common Stock 10000 I Via C. Kellogg & P Kellogg TTEE U/W Charles A Kirkland Trust Common Stock 35000 I Via the Myth and Barnegat Restoration Society, Inc. Common Stock 10000 I Via C. Kellogg & P Kellogg TTEE U/W Anne Kirkland Trust Common Stock 100000 I Via Acceptance Casualty Common Stock 225000 I Via Acceptance Indemnity Common Stock 630000 I Via Wilshire Common Stock 540000 I Via Transguard /s/ Marguerite Gorman, attorney-in-fact 2026-07-08