I don't understand....
How any organisation, but particularly any govt. owned one, can have the sheer brass neck to put out a contract that specifies a random subset of potential suppliers. I can understand a quality threshold e.g. "Must have a successful history of supplying x", ironically seems to be missing from UK requirements (Capita et al). Or a national security one, such as only companies owned within its borders. Or an ethical one, that the companies must meet some specified threshold. But not simply listing a subset of the various ones available because it wants to.That's just an entry level pathway to corruption and back handers. As well as simply being transparently perverse.