Mr. John Burzynski reports

ISS AND GLASS LEWIS RECOMMEND OSISKO SHAREHOLDERS VOTE FOR THE PLAN OF ARRANGEMENT WITH GOLD FIELDS

Institutional Shareholder Services Inc. (ISS) and Glass Lewis & Co., two leading independent proxy advisory firms that provide voting recommendations to institutional investors, have each recommended that shareholders of Osisko Mining Inc. vote for the acquisition of all of the issued and outstanding common shares of Osisko by Gold Fields Ltd., through its 100-per-cent-owned Canadian subsidiary, by way of a statutory plan of arrangement under the Business Corporations Act (Ontario). Shareholders will be asked to vote on the arrangement at the upcoming special meeting of shareholders scheduled to be held on Oct. 17, 2024, at 10 a.m. Toronto time.

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 approximate 55-per-cent premium to the 20-day volume-weighted average trading price per share on the Toronto Stock Exchange for the period ending Aug. 9, 2024, being the last trading day prior to the announcement of the arrangement.

Two independent proxy advisory firms -- ISS and Glass Lewis -- have recommended that shareholders vote for the arrangement.

In its recommendation, ISS noted that the consideration represents a significant premium to the price of the shares prior to the announcement of the arrangement, that the valuation of Osisko appears credible and that the board of the directors of Osisko engaged in a robust process in reviewing the proposal from the purchaser.

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 Street 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.

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.