14 - by its authority shall be exempt, as to principal and interest, from taxation by the Government of the United States or by the government of Guam, or by any State or Territory or any political subdivision thereof, or by the District of Columbia." The Secretary of the Interior (hereafter in this section referred to as Secretary’) is authorized to guarantee for purchase by the Federal Financing Bank bonds or other obligations of the Guam Power Authority maturing on or before December 31, 1978, which shall be issued in order to rehinance short-term notes due or existing on June 1, 1976 and other indebicdness not evidenced by bondsor notes in an aggregate amount of not more than $36 million, and such bank, in addition to its other powers, is authorized to purchase, receive or otherwise acquire these same. The interest rate on obligations purchased by the Fedcral Financing Bankshall be not less than a rate determined by the Secre- tary of the Treasury taking into consideration the current average market yield on outstanding marketable obligations of the United States of comparable maturities, adjusted to the nearest one-eighth Secretary determines that the Guam Power Authority will not meet its obligation to payinterest, the Secretary shall request the Secretary of the Treasury to deduct such payments from sums collected and paid pursuant to Section 30 of this Act (48 U.S.C, 1421h).] The Secretary, with the concurrence of the Secretary of the Treasury,” and end with the words “Section 30 of this Act (48 U.S.C. 1421h),”, and substituting therefor the following language: “The Secretary, upon finding that the Guam Power Authority is unable to refinance the above-mentioned indebtedness by December 31, 1980, shall extend the guarantee provision of this section until. December 31, 2019. Such guaranteed bonds or other obligations shall, while outstanding, include a provision for semiannual payments of interest only until December 31, 1980, and thereafter include a provision for quarterly payments of principal. If the Secretary determines before December 31, 1980, that the Guam Power Authority will not meet its obligation to pay interest, the Seeretary shall request the Secretary of the Treasury to deduct such payments from sums collected and paid to the government of Guam pursuant to seetion 30 of this Act (48 USC. 142th). Should the guarantees be eatended beyond December 1, 1980, (1) the Secretary of the Treasury shall automatically deduct (and pay to the Federal Financing Bank) such payment of principal from sums collected and paid to the government of Guam pursuant to section 80 of this Act, and (2) Guam Power Authority payments of principal and interest shall be paid to the government of Guam, * * * oe * * * Sec. 30. (#) ATL customs duties and Federal income taxes derived from Guam. the proceeds of all taxes collected under the internal revenue laws of the United States on articles produced in Guam and transported to the United States, its Territorics, or possessions, or consumed in Guam, and the proceeds of any other taxes which inay ne sae te oe haa = emetme * em woe SsBe of 1 per centum, plus £ per centum per annum. (The Seerctary, with the concurrence of the Secretary of the Treasury, may extend the - guarantee provision of the previous sentence until December 31, 1950. Such guaranteed bonds or other obligations shall, while outstanding, include a provision for semiannual payments of Interest only. If the