3. The directors general of operations, holders of equivalent positions and the director of administration and finances are authorized to sign, for their branch, the following documents up to the amount specified:
(1) supply contracts and contracts for the purchase or rental of immovables for less than $100,000;
(2) construction contracts for a total of less than $100,000 and orders for changes to construction contracts for less than $10,000;
(3) professional or auxiliary services contracts for a total of less than $100,000;
(4) contracts for concessions or joint ventures where the annual sales figures are less than $100,000;
(5) contracts for the alienation of movables for less than $10,000.