They might not be true banks, but lots and lots of companies become enough of a bank to issue loans or credit cards... to customers that want to buy their products. e.g. car companies, department stores, gasoline companies, etc.
I had a buddy that worked for Caterpillar Finance, the credit arm of the folks that make heavy machinery like bulldozers. They issue loans to companies for purchasing their stuff, etc.
Is this true? I can think of GE, but who else? What percentage of 100+ yo companies do this?