There's no such thing like public. It's always someone's property. We have "public" oil company in Poland and it's only a battlefield of political parties - who will put their man into the company's mgmt. There's gas price manipulation, there's monopoly and other nasty things.
Please learn on others' mistakes and create a subsidy for private companies (a few minimum) instead
This is already a highly successful model in Canada. We have many, many Crown Corporations as well as arms length, publicly owned corporations. Several of these crown corps have become successful enough that they are sold off to become private sector businesses as well.
I think a good balance for public sector and publicly owned corporations would be to mandate that any publicly owned company is given oversight by a different level of government (for example, Federal crown corps/publicly owned corporations should have an oversight board appointed by the provincial governments, provincial crown corps should have oversight appointed by municipal governments or federal government, etc), and there should be regular reporting and quarterly statements similar to what we would expect of publicly traded companies, even if they don't have the same fiscal accountability requirements.
Please learn on others' mistakes and create a subsidy for private companies (a few minimum) instead