Mr. John Burzynski reports

OSISKO ANNOUNCES CONVERSION OF NORTHERN STAR DEBENTURE; REMINDS SHAREHOLDERS TO VOTE FOR THE PLAN OF ARRANGEMENT WITH GOLD FIELDS

Northern Star Resources Ltd. has elected to convert its $154-million of a convertible senior unsecured debenture due Dec. 1, 2025, for 38.5 million common shares of Osisko Mining Inc. at a price of $4 per share.

Northern Star has elected to convert the debenture for shares to participate in the arrangement (as defined herein) as a shareholder of Osisko. The arrangement was previously announced on Aug. 12, 2024, pursuant to which, among other things, Gold Fields Holdings Co. Ltd., through a 100-per-cent-owned Canadian subsidiary, Gold Fields Windfall Holdings Inc., agreed to acquire all of the issued and outstanding shares of Osisko. The shares issued to Northern Star upon the conversion of the debentures were issued subsequent to the record date for the special meeting (as defined herein) and are therefore not eligible to vote on the arrangement at the special meeting.

Special meeting to approve arrangement

Osisko has called a special meeting of its shareholders, scheduled to be held on Oct. 17, 2024, at 10 a.m. Toronto time, where shareholders of Osisko will be asked to vote on the arrangement.

Under the terms of the arrangement, each shareholder will be entitled to receive $4.90 per share upon completion of the arrangement. The consideration represents an approximately 55-per-cent premium to the 20-day volume-weighted average trading price per share on the Toronto Stock Exchange for the period ended Aug. 9, 2024, being the last trading day prior to the announcement of the arrangement.

On the unanimous recommendation of the special committee, the board of directors of Osisko unanimously recommends that shareholders vote for the arrangement.

Your vote is important -- please vote today.

The proxy voting deadline is 10 a.m. Toronto time on Tuesday, Oct. 15, 2024.

Special meeting details

The special meeting is scheduled to be held on Thursday, Oct. 17, 2024, at 10 a.m. Toronto time at the offices of Bennett Jones LLP, located at One First Canadian Place, 100 King St. W, Suite 3400, Toronto, Ont., Canada, M5X 1A4. The management information circular of Osisko dated as of Sept. 6, 2024, together with the associated materials relating to the special meeting, are available on SEDAR+ under Osisko's issuer profile. Shareholders are encouraged to review the special meeting materials prior to voting on the arrangement.

Shareholder questions

Shareholders who have questions about the special meeting or require more information or assistance in voting should contact Osisko's strategic shareholder adviser and proxy solicitation agent, Laurel Hill Advisory Group, at the following.

North America toll-free number:  1-877-452-7184

Collect calls outside North America:   1-416-304-0211 (for shareholders outside Canada and the United States)

By e-mail:  assistance@laurelhill.com

About Osisko Mining Inc.

Osisko is a mineral exploration company focused on the acquisition, exploration and development of precious metal resource properties in Canada. Osisko holds a 50-per-cent interest in the high-grade Windfall gold deposit, located between Val d'Or and Chibougamau in Quebec, and holds a 50-per-cent interest in a large area of claims in the surrounding Urban Barry area and nearby Quevillon area (over 2,300 square kilometres).

We seek Safe Harbor.