Item 1.

(a) Mercer International Inc

(b)     Suite 1120, 700 West Pender St
	Vancouver, BC  V6C 1G8
	Canada


Item 2.

(a) Platinum Investment Management Limited

(b) Level 8, 7 Macquarie Place
    Sydney NSW 2000
    Australia
(c) Australia
(d) Common Stock
(e) 588056101

Item 3.
(e) An IA in accordance with Section 240.13d-1(b)(1)(ii)(e)

Item 4.

(a) 7,666,671
(b) 13.7%
(c) (i) 7,666,671
(ii) 0
(iii) 7,666,671
(iv) 0

Item 5
No

Item 6
The clients of Platinum Investment Management Ltd including pooled
investment vehicles and other managed accounts have the right to
receive or power to direct the receipt of dividends from, and the
proceeds from the sale of, Mercer International Inc.

Item 7
N/A

Item 8
N/A

Item 9
N/A



Item 10
(a) By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were not acquired and are not
held for the purpose of or with the effect of changing or influencing
the control of the issuer of the securities and were not acquired and
are not held in connection with or as a participant in any transaction
having that purpose or effect.
(b) N/A


After reasonable inquiry and to the best of my
knowledge and belief, I certify that the information
set forth in this statement is true, complete and correct.