Article 351 of Civil Code

1 - If the creditor releases one of the joint and several debtors, the remaining debtors shall not be discharged unless the creditor expressly declares this. 2 - If the creditor makes no such declaration, the creditor may demand from the remaining joint and several debtors the balance of the debt after deducting the share of the debtor whom the creditor released. Nevertheless, the creditor may demand from them the entire debt if the creditor has reserved this right. In this latter case, those debtors shall have a right of recourse against the debtor in whose favor the release was granted for the amount of that debtor’s share of the debt.