The pre-emption right exists for co-owners, protecting them from unwanted outsiders.
Conditions
1) Co-ownership (not condominium), 2) Sale to a third party (not another co-owner), 3) Notice of sale, 4) Payment of the price within 3 months.
Time limit
3 months from formal notice. Without notice: 2 years from registration of the sale.
Court
The general civil court where the property is. Suit is filed against the selling co-owner and the new buyer.
Price
The actual sale price plus registry fees and taxes. Must be deposited in court before or during the suit.
Effect of judgment
The third-party sale is annulled and the share passes to the pre-empting co-owner.
When pre-emption does not apply
Gifts (no sale), sale to another co-owner, sales to ascendants/descendants. Condominium has its own rules.