When you are talking about the type of assigned Public IP space you have there are a couple of terms that are handy to know.
Provider assigned (PA) space. This is space assigned by your upstream provider. These “belong” to someone you are buying services from. If you wish to advertise these via your own ASN to other providers you need a Letter of Authority (LOA) from whom these IPs are assigned to.
Provider independent (PI) is space directly assigned to you from a registry such as ARIN, RIPE,etc. These addresses “belong ” to you. You have authority over these addresses to assign them out, as long as it meets the terms set by the registry.