When a company steals sales form itself, this is referred to as cross-subsidization of its business unit?

True. Cross-subsidization occurs when profit is taken from one product and put into another product. A business will charge more money for one product, and thus, will be charging one customer base more money for that same product. Then, the money made from the increase in charge of that product will be put into the second product. This results in a company 'stealing' sales from itself.