February 24, 2026
We act for mining companies, providing a broad range of services. But we do not act on securities law issues.
So why are we writing an article about securities law?
Because it affects mining companies operationally as well as under securities regulation.
In Lundin Mining Corp. v. Markowich the Supreme Court of Canada considered the meaning of “material change” under the Ontario Securities Act, which requires disclosure “forthwith” of any “material change” in the company’s “business, operation or capital”.
“Material change” is not a defined term under the Act, so it is subject to interpretation within the factual context in issue. This is a basic principle of contract interpretation, newly articulated 20 years ago, but standard enough now that if you work with contracts at all, you should be aware of the need to look beyond the words on the paper and consider how your unique circumstances.
Common sense is the standard, which unfortunately leaves a lot of grey areas. This uncertainty creates business risk.
In this particular case, the company experienced pit instability and a pit wall collapse. This would affect the forecasted production of the mine by twenty per cent in the following year. The Plaintiffs complain that the company did not disclose this event forthwith.
The Court says that a change, to be material, does not need to be “important or substantial” to be “material”. What is crucial to the interpretation in this case is that securities legislation is intended to “level the playing field” and protect investors. This means that any doubt as to materiality is likely to be interpreted in favour of disclosure.
This appeal was only about whether there might have been material change, not about the ultimate outcome. However, since it sets a high bar requiring more disclosure, as explained above, it should send a chill through your spine if you are part of the disclosure process.
TAKEAWAYS
- The obligation is on the securities issuer to disclose a material change forthwith.
- Understanding “material change” is nuanced, but the ultimate question is “might it affect the stock price?”
- Failure to disclose can have expensive consequences.
- Any significant change in business, operations or capital may be alleged to be “material”.
- If in doubt, seek legal advice.
HOW WEILERS LLP CAN HELP YOU
Weilers LLP’s proud tradition in mining law goes back to our roots. Before Biff and Bernie Weiler combined their practices in Fort William (now Thunder Bay) 75 years ago, they got their starts in Red Lake and Hardrock mining camp (Geraldton) respectively. We now combine that tradition with a progressive approach that reflects our extensive work with resource industries, investors, lenders and First Nations.
We are not the lawyers who will advise you on whether to disclose your change. We will send you to your securities lawyers for that advice. We know what we are good at.
What we are good at is advising and representing you on a wide range of business and operational matters, ranging from options, joint venture and royalty agreements; to energy supply agreements, indigenous relations, property questions, employment law, and dealing with contractors.
If you need lawyers who practice close to where the action is, and know what they are good at, give us a call. We may be the right lawyers for you.