September 23, 1981

Treasury Secretary Donald T. Regan, the Administration's chief economic spokesman, today rejected the idea of balancing the Federal budget by delaying or modifying the 25 percent tax-rate cut for individuals enacted in August. ''Spending reduction is the only route to a balanced budget,'' Mr. Regan told the House Budget Committee. The Treasury chief reaffirmed that the Administration would seek an additional $16 billion of spending cuts for the 1982 fiscal year, which starts Oct. 1, as essential to bringing the budget deficit down to $42.5 billion. For the fiscal year 1981, which ends on Sept. 30, the deficit will be $55 billion or a bit more.

A little more than a decade ago, the Nucor Corporation bought steel angles from the large steel companies, turned them into joists and sold them to commercial builders. Then, Kenneth Iverson, its president, decided that his company could bypass the steel companies by producing its own steel angles. His calculations showed that Nucor could produce steel at less cost than the domestic companies and even the Japanese. As a result, Nucor went into the steel business by opening minimills, and today its production from these mills accounts for 50 percent of its sales and revenue. In the past decade, dozens of other companies have also learned about the advantages of mini-steel mills, which have become a significant factor in the industry.

A picture caption in yesterday's Metropolitan Report misidentified David N. Dinkins, candidate for Manhattan Borough President. He is the City Clerk.

AM International Inc. announced yesterday that it would report a loss of $175 million in the 1981 fiscal year and that it planned to sell its Addressograph and Jacquard divisions to relieve its debtladen balance sheet. Analysts called the size of the loss surprising, but said the sale of two more divisions was consistent with the policy of Richard B. Black, chairman, to cut away unprofitable lines to create a solid base upon which to rebuild the office equipment manufacturer. President Resigns Mr. Black, who assumed control of AM International last February, replacing Roy L. Ash, also announced that James R. Mellor, president, had resigned, following the announcement of the 1981 losses.

Tens of thousands of students in New York City public schools may fail to meet the deadline set for today to conform with the state's new regulations requiring immunization against childhood diseases, school officials said yesterday. The officials have vowed that beginning tomorrow such youngsters will be barred from attending school, but a similar requirement last fall went largely unenforced even though 28,904 students did not comply. ''There are distinct differences between last year and this year,'' said Robert H. Terte, a spokesman for the school system. ''The Health Department is auditing the schools now and is pressing for enforcement and, moreover, the Chancellor has instructed the schools not to admit students who are not in compliance.''