There is no law that will prevent you from starting a business, owning its shares and earning dividends. Businesses (as long as they are correctly established under the law) are considered both separate legal persons and property and anyone, no matter what their status in Canada is, is allowed to own property in Canada. The business, if it was either incorporated in Canada or does foreign qualify under the law of the province, is authorized to conduct business in Canada.
You probably want to work for that business. Here is when it gets tricky. As an officer of a corporation you would be considered an employee for tax purposes and the money the corporation pays you as remuneration for services rendered are wages. In addition any services that you render to the corporation that are competing with the services offered by the Canadian workforce. Therefore, you would likely be considered a worker for immigration purposes.
If you are a worker in Canada (and not a citizen or PR), you need to be in possession of a work permit that is either unrestricted (open) or specific for the employer you work for. If you want to work for your own business, you need to have a work permit issued with the name of that business in the employer field.
If you have an employer-specific work permit for a different employer, then you should look into your options to get a new work permit. Since you already have a work permit, you can apply in Canada for a new one. You may also be exempt from an LMO under certain conditions (look up C11 or C12 in the foreign worker's manual).
