The CEO of the company that operates the Toronto Stock Exchange says most of this country's small- and mid-sized companies are unprepared for expected new climate disclosure requirements.

Canadian securities regulators are currently considering adopting a new rule that would require publicly traded companies in Canada to disclose to investors a range of information related to climate change and their company's environmental impact.

These new rules could include requirements to report all of a company's greenhouse gas emissions, including those they produce indirectly, such as when a customer uses their product.

The rules could also require companies to disclose the risk posed by climate change and the energy transition to their business.

John McKenzie, CEO of TMX Group, said Thursday at an Alberta Securities Commission conference that smaller publicly traded companies in Canada don't have the capacity, capability or resources to provide that level of detail.

He says the initial rollout of climate disclosure rules in Canada will need to provide exemptions for small-cap issuers, as well as generous time frames for larger companies to come into compliance with some of the more challenging requirements.