Anita Soni

Tanya Jakusconek

Carey MacRury

Mohamed Sidibe

Steven Green

Lawson Winder

Matthew Murphy

Michael Parkin

Wayne Lam

- **IAMGOLD Corporation** has signed a definitive arrangement agreement to acquire **Mines D'Or Orbec Inc.** in a cash and shares transaction.  **[1203464_0001062993-25-016205_exhibit99-1.htm:0]** 
- Orbec shareholders will receive **C$0.0625 per Orbec Share** in cash and **0.003466 of an IAMGOLD common share** for each Orbec Share, implying a total equity value of **C$17.2 million** and representing a **25% premium** to Orbec's closing price on October 17, 2025.  **[1203464_0001062993-25-016205_exhibit99-1.htm:0]** 
- This acquisition will consolidate IAMGOLD's land position in the Chibougamau district of Quebec, adding the **highly prospective Muus Project** and its **24,979 hectares** of mineral rights, adjacent to IAMGOLD's Nelligan and Monster Lake Projects.  **[1203464_0001062993-25-016205_exhibit99-1.htm:0]** 
- The transaction is expected to close in the **fourth quarter of 2025**.  **[1203464_0001062993-25-016205_exhibit99-1.htm:1]**

IAMGOLD to Acquire Mines D'Or Orbec Inc.

- IAMGOLD Corporation has agreed to acquire Northern Superior Resources Inc. in a transaction valued at approximately **$267.4 million**.  **[1203464_0001062993-25-016203_exhibit99-1.htm:0]**  Northern Superior shareholders will receive **0.0991 IAMGOLD common shares** and **C$0.19 in cash** for each share, representing a **27.4% premium** based on 20-day volume-weighted average prices as of October 17, 2025.  **[1203464_0001062993-25-016203_exhibit99-1.htm:0]** 
- The acquisition will create the "Nelligan Mining Complex" by combining IAMGOLD's Nelligan and Monster Lake projects with Northern Superior's Philibert, Chevrier, and Croteau deposits.  **[1203464_0001062993-25-016203_exhibit99-1.htm:0]**  This complex is estimated to host **3.75 million ounces of gold (Moz Au)** in Measured and Indicated Mineral Resources and **8.65 Moz Au** in Inferred Mineral Resources.  **[1203464_0001062993-25-016203_exhibit99-1.htm:0]** 
- The transaction significantly expands IAMGOLD's landholding in Quebec's Chibougamau district by adding **70,636 hectares**, bringing the total to over **109,000 hectares**, and positions the Nelligan Mining Complex as the **4th largest pre-production gold camp in Canada**.  **[1203464_0001062993-25-016203_exhibit99-1.htm:0]** 
- The transaction is anticipated to close in the **fourth quarter of 2025 or first quarter of 2026**, pending shareholder and regulatory approvals.  **[1203464_0001062993-25-016203_exhibit99-1.htm:1]**

IAMGOLD to acquire Northern Superior Resources

- **IAMGOLD Corporation** has entered into definitive agreements to acquire **Northern Superior Resources Inc.** and **Mines D'Or Orbec Inc.**, consolidating significant land and deposits in Quebec, Canada.  **[1203464_d3c1fa9d54eb4313ba9bfbf348550af2]** 
- The acquisition of Northern Superior aims to form the **Nelligan Mining Complex**, projected to be one of Canada's largest pre-production gold camps, with **3.75 million ounces of gold in Measured and Indicated Mineral Resources** and **8.65 million ounces of gold in Inferred Mineral Resources**.  **[1203464_d3c1fa9d54eb4313ba9bfbf348550af2]** 
- Northern Superior shareholders will receive **0.0991 of an IAMGOLD common share plus cash** per share, while Orbec shareholders will receive **C$0.0625 in cash plus 0.003466 IAMGOLD shares** per share.  **[1203464_d3c1fa9d54eb4313ba9bfbf348550af2]** 
- These strategic acquisitions are expected to significantly expand IAMGOLD's Canadian gold portfolio and reinforce its long-term growth strategy.  **[1203464_d3c1fa9d54eb4313ba9bfbf348550af2]**

IAMGOLD Acquires Northern Superior and Mines D'Or Orbec

- IAMGOLD Corporation announced positive assay results from its **2025 drilling programs** at the Nelligan and Monster Lake Projects in central Quebec, Canada, confirming the extension of mineralized zones.  **[1203464_0001062993-25-015714_exhibit99-1.htm:0]** 
- The combined Nelligan and Monster Lake camp now boasts nearly **9 million ounces of resources**, positioning Nelligan among Canada's largest gold projects.  **[1203464_0001062993-25-015714_exhibit99-1.htm:0]** 
- Significant drilling intercepts at Nelligan include **20.6 meters at 1.93 g/t Au** in Zone 36 and **13.5 meters at 3.15 g/t Au** in the Renard Zone.  **[1203464_0001062993-25-015714_exhibit99-1.htm:0]** 
- High-grade results from Monster Lake include **9.0 meters at 23.4 g/t Au** in the Megane Zone and **4.9 meters at 127.3 g/t Au** in the Lower Shear Zone.  **[1203464_0001062993-25-015714_exhibit99-1.htm:0]** 
- As of December 31, 2024, Nelligan's estimated Mineral Resources comprise **3.1 million ounces of Indicated Resources** and **5.2 million ounces of Inferred Resources**, while Monster Lake's estimated Mineral Resources include **84,200 ounces of Indicated Resources** and **488,500 ounces of Inferred Resources**.  **[1203464_0001062993-25-015714_exhibit99-1.htm:2]** **[1203464_0001062993-25-015714_exhibit99-1.htm:3]**

IAMGOLD (IAG)