Building a multibillion-dollar investment manager from a government report turns out to be a legal as well as an organizational challenge. That is the lesson Allen Garson drew from helping to launch the Investment Management Corporation of Ontario (IMCO), where he became the first general counsel and inherited the task of building the legal foundations needed to support the organization and its consolidation mandate.
IMCO grew out of a 2012 review that recommended pooling Ontario’s fragmented public-sector funds, and it opened in July 2017, with Garson arriving a month later. The Toronto-based investor manages assets for the province’s broader public sector, and his early years were defined by helping convert that founding mandate into something that functioned more efficiently and with improved integration across the organization.
Garson oversaw the establishment of IMCO’s pooled funds structure. This multi-year effort consolidated $52 billion in client assets across a wide range of asset classes to create greater scale and efficiency, he says. Two founding clients had previously been run on a segregated basis, each with its own strategy, objectives and capital pool. Merging the pools and investing client assets in accordance with IMCO’s investment strategies was a significant challenge for a new organization. The pooling project, as it was known internally, “wasn’t just about creating legal structures. That was the easy part of the job,” he says. The harder part was institutional: “This organization was young, effectively an early merger and startup, and didn’t have the necessary integration across the organization just yet,” he says. The pooling project became as much about building and integrating finance, operations, investments and risk capabilities as it was about structuring entities – a challenge he says was as complicated as any the organization has faced.
But the effort paid off. Today, IMCO has matured into one of Canada’s largest institutional investors, managing more than $90 billion in assets across eight clients.
Garson came to IMCO after decades in private practice, most of them at Heenan Blaikie LLP, which he joined when its Toronto presence was barely formed. “I started at Heenan’s when the Heenan Toronto office had just opened, and I think I was the seventh lawyer in the Toronto office,” he says. His practice spanned media and entertainment to energy mergers and acquisitions, including renewables, with work for clients such as Brookfield Renewable and Berkshire Hathaway Energy.
Then the firm collapsed. Garson stayed “right until the end in 2014,” and the dissolution forced an abrupt transition. “In 2014, when Heenan’s closed the doors, I, together with a group of about 45 or so other people, went over to Dentons Canada,” he says, where he became co-head of the national M&A practice. He was steering that move while closing Berkshire Hathaway Energy’s acquisition of AltaLink, its first major Canadian deal. “Trying to hold all that together with a young family was not easy,” he says.
The shift in-house grew out of that M&A work. As he spent more time treating pension funds as a source of capital for global deals, he came to know the sector, and an introduction to IMCO president and chief executive Bert Clark followed. What drew him was the mandate itself. “The idea that it was in the public sector and for a really important public purpose was … really intriguing to me,” he says – that, and the rare chance to build a legal department, with oversight of the related compliance, governance and public affairs departments, from scratch.
That build shaped how Garson runs IMCO’s legal function today. He keeps the structure flat, pushes his lawyers to embed with the business rather than wait to be asked, and treats trust as the currency that makes it work. “Trust comes in on foot and leaves on horseback,” he says, and “it takes a long time to earn it, and you can lose it really quickly.” The aim is for the team to operate as partners: “I think our team is very good at trying to be a real business partner as opposed to just a service provider,” he says.
Much of what reaches his desk, he notes, “aren’t really legal questions or legal problems” so much as pieces of larger business puzzles with legal issues embedded inside them. “In the investment community, we talk about risk-adjusted returns,” he says, so he thinks of his legal team as providing “risk-adjusted advice.” No option is ever clean: “There’s no problem that doesn’t have risk, and there’s no solution that doesn’t have risk,” he says.
Those instincts are also what Garson screens for when hiring. The right candidate “is somebody who brings a broad toolkit” and is willing to “stretch,” he says. It can take private practitioners a bit longer to make the leap. “They’re great at spotting the issues. They’re great at giving you the analysis,” he says. Still, many stop short of judging whether a given risk is acceptable against the organization’s goals – the same gap many other general counsel describe after moving in-house from private practice.
Garson expects artificial intelligence to widen that gap rather than close it. Independent research from FTI Consulting found more than two-thirds of general counsel are interested in using generative AI in their legal departments, and the Association of Corporate Counsel reported in its 2025 law department management benchmarking report that AI use in corporate legal departments climbed to 52 percent in 2025 from 34 percent a year earlier. He sees that adoption as a reason to invest in judgment, not retreat from it. “I think AI is going to make that even harder to be honest and more valuable,” he says, because business teams will arrive “armed with much more sophisticated information, rightly or wrongly.”