Clark, who headed an expert panel on government assets, is still looking at other aspects of alcohol sales, such as wine and spirits.
In his new business adviser role, Clark will provide advice on "growing a vibrant and dynamic economy in Ontario" and moving to a knowledge-based economy.
It comes as the Liberal government aims to cut a $10.9-billion deficit by 2017-18.
As with his asset panel work, Clark will not be paid a salary for his role as business adviser, but will be reimbursed for "reasonable" expenses.
Clark is set to provide his business recommendations next spring.
NDP finance critic Catherine Fife said the appointment will leave Ontarians, "stuck with the bill," citing contracts worth up to $7.5 million that were awarded to companies and consultants who helped Clark with his Hydro One and beer report.
"Let's remember the last time Ed Clark did 'unpaid' work," Fife said in a statement.