The Michigan Public Service Commission on Sept. 28 approved settlements that will return a total of about $7.6 million under the second round of federal tax cut adjustments to electric customers of Alpena Power Co. and Upper Michigan Energy Resources Corp., and gas customers of Michigan Gas Utility Corp., Northern States Power, SEMCO Energy Gas Co., and Upper Michigan Energy Resources. The adjustments called Credit B determine refunds from Jan. 1 until the date when the first round called Credit A adjustments were reflected in customer bills. The commission so far authorized about $379.5 million in rate cuts for 10 regulated utilities under the first round. In August, the commission approved the first Credit B reduction of $135,383 for Northern States Power Co. The commission established the three-step process to reflect the short- and long-term impacts of the federal tax law which slashed the corporate income tax rate to 21 percent from 35 percent.