(a) As used in this section (1) with regard to electric power, “sales for resale” include (A) sales of electric power capacity, (B) power output from such capacity, and (C) all transmission charges in conjunction with such sales on or after May 17, 1982, (2) “net invoice price” means invoice price less trade discounts, and (3) “municipal utility” means a municipality, or department or agency thereof, or district manufacturing, selling or distributing gas or electricity to be used for light, heat or power.

(b) (1) Each company included in § 12-264, other than an electric distribution company, as defined in § 16-1, included in subsection (c) of § 12-264, shall be taxed at the rate of five per cent upon the amount of gross earnings in each taxable quarter from operations, except as set forth in subsection (c) or (d) of this section and except that each company shall be taxed at the rate of four per cent upon the amount of gross earnings in each taxable quarter allocable to residential service, but deduction shall be made of gross earnings (A) from all sales for resale of water, steam, gas and electricity to public service corporations and municipal utilities, whether or not such purchasers are Connecticut public service corporations or Connecticut municipal utilities, and whether or not they are subject to the tax imposed by this chapter, (B) from any federal BTU energy tax included in adjustment clause and base-rate revenues, (C) from sales of appliances using water, steam, gas or electricity by each such company of the net invoice price plus transportation costs of such appliances, (D) of electric distribution and gas companies, as defined in § 16-1, from energy conservation loan programs, (E) from all sales for resale of gas to companies registered pursuant to § 16-258a, and (F) from all sales of natural gas to a user or entity located outside the state.

(2) Gross earnings for any taxable quarter, for the purposes of assessment and taxation, shall be as follows: (A) In the case of a company carrying on business or operating entirely within this state, the amount of gross earnings from operations; (B) in the case of a company carrying on business or operations a part of which is outside of this state, (i) such portion of the amount of gross earnings from operations determined under the provisions of § 12-264 as is represented by the ratio of the number of miles of water or steam pipes, gas mains or electric wires operated by such company within this state on the first day and on the last day of the calendar year immediately preceding to the total number of miles of water or steam pipes, gas mains or electric wires operated by such company on such dates; or (ii) in the case of a company required to register pursuant to § 16-258a, such portion of the amount of gross earnings from operations determined under the provisions of § 12-264 as is represented by the ratio of the sales in this state to end users during such quarter to the total sales everywhere to end users during such quarter.

(c) (1) The rate of tax on the sale, furnishing or distribution of electricity or natural gas for use directly by a company engaged in a manufacturing production process, in accordance with the Standard Industrial Classification Manual, United States Office of Management and Budget, 1987 edition, classifications 2000 to 3999, inclusive, or Sector 31, 32 or 33 in the North American Industrial Classification System United States Manual, United States Office of Management and Budget, 1997 edition, shall be four per cent with respect to calendar quarters commencing on or after January 1, 1994, and prior to January 1, 1995, three per cent with respect to calendar quarters commencing on or after January 1, 1995, and prior to January 1, 1996, and two per cent with respect to calendar quarters commencing on or after January 1, 1996, and prior to January 1, 1997. The sale, furnishing or distribution of electricity or natural gas for use by a company as provided in this subsection shall not be subject to the provisions of this chapter with respect to calendar quarters commencing on or after January 1, 1997. Not later than thirty days after May 19, 1993, and thirty days after the effective date of each rate decrease provided for in this section, each electric and gas public service company, as defined in § 16-1, which does not have a proposed rate amendment under § 16-19 pending before the Public Utilities Regulatory Authority at such time, shall request the authority to reopen the proceeding under § 16-19 on the company’s most recent rate amendment, solely for the purpose of decreasing the company’s rates to reflect the decreases required under this section. The authority shall immediately reopen such proceedings, solely for such purpose.

(2) For purposes of this subsection, the sale, furnishing or distribution of natural gas for use as fuel in the operation of a cogeneration facility providing electricity or steam to a company engaged in a manufacturing production process described in subdivision (1) of this subsection shall be deemed to be a sale, furnishing or distribution of natural gas for use directly by such company in such process where such cogeneration facility is located entirely on the premises owned or controlled by such company, whether or not the cogeneration facility is owned or operated by such company.

(d) The rate of tax on the sale, furnishing or distribution of steam for use by a company, as described in subparagraph (B) of subdivision (1) of subsection (a) of § 12-264, shall be: (1) Four per cent with respect to calendar quarters commencing on or after July 1, 1996, and prior to July 1, 1997; (2) three per cent with respect to calendar quarters commencing on or after July 1, 1997, and prior to July 1, 1998; (3) two per cent with respect to calendar quarters commencing on or after July 1, 1998, and prior to July 1, 1999; and (4) one per cent with respect to calendar quarters commencing on or after July 1, 1999, and prior to July 1, 2000. The sale, furnishing or distribution of steam as provided in this subsection shall not be subject to the provisions of this chapter with respect to calendar quarters commencing on or after July 1, 2000.