Is it permissible to purchase building permits, by virtue of which a certain quantity of cement is obtained, from their owners who may not need them except for trading purposes, and then sell the cement in the market? And does this fall under the category of a person selling what he does not possess?

If the buyer purchases cement that is still in storage, this falls under the category of selling what has not yet been taken possession of. This is a matter of scholarly disagreement, except for food, concerning which there is a consensus on the impermissibility of selling it before taking possession. The preponderant opinion in this case is permissibility, due to the minimal nature of the uncertainty (gharar (definition)). However, if the buyer is purchasing only the license to deal in cement, this falls under the assignment of rights for financial compensation.