Form 6-K Summary: Colliers International Group Inc.

This Form 6-K, filed November 4, 2025, serves primarily to submit Exhibit 99.1, which contains the press release announcing financial results for the third quarter ended September 30, 2025.

Key investor takeaways are contained within the linked exhibits:

• Financial Reporting: Q3 2025 financial results are disclosed via Exhibit 99.1.
• Supplemental Data: A corresponding slide presentation is attached as Exhibit 99.2.
• Regulatory Note: Exhibit 99.1 is incorporated by reference into the registrant’s pending Form F-10