All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.
If you completely own this land [i.e. this land became totally in your possession and you became its owner], then it is permissible for you to sell it to that person and for him to pay the installments and pay you an additional amount.
However, if you do not possess the land, then it is not permissible for you to sell it. The same applies if the corporation prevents you from selling this land before paying all the installments, as the land in that case will be mortgaged [as collateral] against the installments, so then it would not be permissible for you to sell it before paying all the installments.
Allaah knows best.