Agnico Eagle Mines (TSX, NYSE: AEM) is investing $57.2 million (US$41.4 million) in Radisson Mining Resources (TSXV: RDS; US-OTC: RMRDF) to help revive O'Brien, one of the Abitibi region's highest-grade historical mines. Following the announcement, Radisson's shares surged to an all-time high.

Under the deal, the Canadian gold major will buy 53.4 million units — each consisting of one Radisson share and one-half of a share purchase warrant — at $1.07 apiece. That price represents a 6% premium to Friday's closing price, Radisson said Monday. The investment will give Agnico a 10.5% stake on a non-diluted basis and as much as 14.9% on a partially diluted basis if the warrants are exercised.

"The advanced underground exploration program that will now commence is designed to extend our understanding of potential mining conditions at O'Brien," Radisson president and CEO Matt Manson said in a release. "This investment by Agnico Eagle will fund the first modern underground access at O'Brien, which will assist us in developing the project's full potential."

The backing expands Agnico's presence in Quebec's Abitibi region — one of Canada's most prolific gold-producing districts — where it already operates the LaRonde, Canadian Malartic and Goldex mines. Agnico is Canada's largest gold producer by output and market capitalization.

The O'Brien mine produced 587,000 oz. of gold from 1.2 million tonnes grading 15.25 grams gold per tonne between 1926 and 1957.

Radisson shares jumped 21% to $1.24 apiece in Toronto on Monday morning, giving the company a market value of $557 million. Over the past year, the stock has traded as low as 53¢.

Underground

The financing will pay for an access ramp, underground workings, surface infrastructure and water management facilities at the site in the Bousquet-Cadillac mining camp along the Larder Lake-Cadillac Break, 470 km northwest of Montreal. Engineering and permitting will begin immediately, while Radisson continues its fully funded 140,000-metre surface drill campaign.

The agreement also grants Agnico board representation and participation rights in future financings, while restricting certain property transactions, royalties, streams and secured financings through the end of 2028.

Radisson is advancing O'Brien as an 11-year underground mine with a $175-million initial capital cost and toll milling at nearby Doyon — an arrangement in which ore is processed at an existing mill rather than a purpose-built plant — according to a July 2025 preliminary economic assessment, an early-stage study of a project's potential economics. Using a gold price of US$3,300 an oz., the study estimated an after-tax net present value of $871 million at a 5% discount rate, a 74% internal rate of return and a one-year payback.

No. 1 core

The project recorded the top gold assay globally during the June 17-July 15 period this year. Drill hole OB-26-385W4 intersected 5.1 metres grading 316.31 grams gold per tonne from 823 metres downhole, for a width-times-grade value of 1,613 — a metres-times-grams measure used to compare drill intercepts. The interval included 1 metre grading 1,603.95 grams gold, the highest assay reported from the historic mine.

That result followed a March resource update that increased inferred contained metal by 82% to 1.69 million oz. gold in 10.4 million tonnes grading 5.08 grams gold. The project also contains 3.49 million tonnes grading 5.59 grams gold, equivalent to 627,000 ounces. Inferred is the lowest-confidence category of mineral resource.