OSK Osisko Mining Inc

 Osisko Mining Inc. ("Osisko") (TSX:OSK) is pleased to announce the successful completion of its previously announced plan of arrangement transaction (the "Arrangement"), pursuant to which, among other things, Gold Fields Limited, through a 100% owned Canadian subsidiary, Gold Fields Windfall Holdings Inc., acquired all of the issued and outstanding common shares of Osisko (the "Shares").

Osisko's Chairman and Chief Executive Officer, John Burzynski, commented:

"This premium transaction represents a strong and near-term outcome for our shareholders and is reflective of the truly world class nature of the Windfall Project. In the span of nine years, we've transformed Windfall into one of the largest and highest-grade gold development projects globally, and this transaction is a testament to the extraordinary entrepreneurial effort of the Osisko Mining team. Gold Fields is a globally diversified senior gold producer with an impressive track record of successfully building and operating mines. As our (now former) joint venture partner at Windfall, Gold Fields knows the asset well and understands the significance of the strong relationships that we have built in Québec with all of our stakeholders. Moreover, Gold Fields share our core principles of operating in a safe, inclusive and socially responsible manner. They are well suited to take Windfall into production and we wish them all the best going forward."

Under the terms of the Arrangement, each former shareholder of Osisko is entitled to receive C$4.90 for each Share (the "Consideration") held immediately prior to the effective time of the Arrangement. A Final Order approving the Arrangement was granted by the Ontario Superior Court of Justice on October 22, 2024. The Arrangement became effective earlier today.

Former registered shareholders of Osisko are reminded that, in order to receive the Consideration to which they are entitled under the Arrangement, they must complete, sign and return the letter of transmittal to TSX Trust Company, in its capacity as depositary under the Arrangement, together with their certificate(s) or DRS advice(s) representing their Shares. If you have any questions or require further information regarding the procedures for receiving the Consideration, please contact TSX Trust Company: (i) by telephone at 1-866-600-5869 (North American Toll Free) or 416-342-1091 (Outside North America); (ii) by facsimile at 416-361-0470; (iii) by email at tsxtis@tmx.com; or (iv) online at www.tsxtrust.com/issuer-and-investor-services.

Former non-registered shareholders should receive the Consideration to which they are entitled under the Arrangement directly in their brokerage accounts. Non-registered shareholders should contact their broker or other intermediary if they have any questions or require further information regarding the procedures for receiving the Consideration to which they are entitled under the Arrangement.

As a result of the completion of the Arrangement, the Shares are expected to be delisted from the Toronto Stock Exchange within two business days of closing. Osisko intends to submit an application to the applicable securities regulators to cease to be a reporting issuer and to terminate its public reporting obligations. Each of the directors and senior officers of Osisko have resigned from their respective positions with Osisko upon completion of the Arrangement.

Further details regarding the Arrangement are set out in Osisko's management information circular dated September 6, 2024 which is available on SEDAR+ (www.sedarplus.ca) under Osisko's issuer profile.

Advisors

Maxit Capital LP and Canaccord Genuity Corp. acted as financial advisors to Osisko. Bennett Jones LLP acted as legal advisor to Osisko. Fort Capital Partners acted as financial advisor to the special committee of independent directors of Osisko (the "Special Committee"). Cassels Brock & Blackwell LLP acted as independent legal advisors to the Special Committee.

About Osisko

Osisko is a mineral exploration company focused on the acquisition, exploration, and development of precious metal resource properties in Canada.

About Gold Fields

Gold Fields is a globally diversified gold producer with nine operating mines in Australia, South Africa, Ghana, Chile and Peru and one project in Canada. Gold Fields shares are listed on the Johannesburg Stock Exchange (JSE) and its American depositary shares trade on the New York Exchange (NYSE).

Cautionary Statement Regarding Forward-Looking Statements

This news release may contain forward-looking statements (within the meaning of applicable securities laws) which reflect Osisko's current expectations regarding future events. Forward-looking statements are identified by words such as "believe", "anticipate", "project", "expect", "intend", "plan", "will", "may", "estimate" and other similar expressions. The forward-looking statements in this news release include all statements that are not historical fact. The forward-looking statements in this news release are based on a number of key expectations and assumptions made by Osisko including, without limitation: the timing and ability of Osisko to cause the Shares of Osisko to be delisted from the Toronto Stock Exchange; and the timing and ability of Osisko to obtain an order that it has ceased to be a reporting issuer and to terminate its public reporting requirements. Although the forward-looking statements contained in this news release are based on what Osisko's management believes to be reasonable assumptions, Osisko cannot assure investors that actual results will be consistent with such statements. The forward-looking statements in this news release are not guarantees of future performance and involve risks and uncertainties that are difficult to control or predict. Several factors could cause actual results to differ materially from the results discussed in the forward-looking statements. Such factors include, among others: currency fluctuations; disruptions or changes in the credit or security markets; results of operations; and general developments, market and industry conditions. Additional factors are identified in Osisko's annual information form for the year ended December 31, 2023 and most recent Management's Discussion and Analysis, each of which is available on SEDAR+ (www.sedarplus.ca) under Osisko's issuer profile. Readers, therefore, should not place undue reliance on any such forward-looking statements. These forward-looking statements are made as of the date of this news release and, except as expressly required by applicable law, Osisko assumes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.

Contact Information:

John BurzynskiChairman & Chief Executive Officer(416) 363-8563