Section 6
SEC. 6. Any provision of law to the contrary notwithstanding, in the execution of the Project, the National Irrigation Administration shall award all contracts for construction and for the purchase of articles, materials, equipment and supplies (including all building materials) financed out of proceeds from loans, credits and indebtedness authorized under Section three of this Act, after international competition as may be required by the lending financial institution, to the lowest responsible bidder, taking into account not only price but also quality, experience and other relevant factors. Any law imposing restrictions on international competitive bidding or granting preferences, including Act Numbered Four thousand two hundred thirty-nine, Commonwealth Act Numbered. One hundred thirty-eight, Commonwealth Act Numbered Five hundred forty-one, Republic Act Numbered Five thousand one hundred eighty-three, and Republic Act Numbered Nine hundred twelve shall not be applicable to such contracts: Provided, however, That preference shall be granted in favor of articles, materials, equipment or supplies of the growth, production of the Philippines, or manufactured in the Philippines substantially from articles, materials, or supplies of the growth, production or manufacture of the Philippines, when offered by bidders who are citizens of the Philippines, or corporations, partnerships, associations or firms duly organized and registered under the laws of Philippines seventy-five per centum of the capital which is owned by citizens of the Philippines, which of preference shall be fifteen percent or such other higher percentage as may from time to time be agreed upon with the foreign or international institution providing financing for the Project: Provided, further, That in comparing the bids: (a) customs duties and any other taxes otherwise due on, or in respect of, imported articles materials, equipment or supplies and any national and local sales taxes thereon due on the sale to the National Irrigation Administration shall, if included in the bid price of a bidder not entitled to preference under this section, be deducted therefrom. The resulting bid price shall then be increased by the rate of preference provided for in this section; (b) national and local sales taxes due on the sale to the National Irrigation Administration of articles, materials, equipment or supplies shall, if included in the bid price of a bidder entitled to preference under this section, be deducted therefrom.