4. Assistant directors general for operations and holders of equivalent positions 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 $50,000;
(2) construction contracts for a total of less than $50,000 and orders for changes to construction contracts for less than $5,000;
(3) professional or auxiliary services contracts for a total of less than $50,000;
(4) contracts for concessions or joint ventures where the annual sales figures are less than $50,000;
(5) contracts for the alienation of movables for less than $5,000.