Cia. Siderurgica Nacional SA (CSNA3), Brazil’s third-largest steelmaker, dropped the most this year after first-quarter profit missed analysts’ estimates.

CSN, as the Sao Paulo-based company is known, fell as much as 3.7 percent to 14.56 reais, the biggest intraday decline since Dec. 8. The stock traded at 14.86 reais at 10:37 a.m.

CSN’s first-quarter net income slumped 82 percent to 110.7 million reais ($56.7 million), or about 8 centavos a share, from 617.5 million reais, 42 centavos, a year earlier, the company said in a statement late yesterday. It was expected to post profit excluding some items of 446.6 million reais, according to the average of nine analyst estimates compiled by Bloomberg.

The earnings decline came as the steelmaker’s net revenue rose 2.8 percent in the quarter to 3.9 billion reais, less than the 23 percent increase in the cost of goods sold. Sales at its iron ore business, its most profitable unit, fell 1.3 percent.

“The main miss was thanks to iron ore, which saw dismal sales,” Banco BTG Pactual SA’s analysts Edmo Chagas and Antonio Heluany said in a note to clients today. “While we believe iron ore volumes will improve and costs will come down, we do not see these factors as capable of meaningfully widening operating margins.”

Iron-ore shipments from Brazil, the world’s second-largest exporter of the steelmaking ingredient, were curtailed this year after heavy rains in the southeast. Gerdau SA and Usinas Siderurgicas de Minas Gerais SA, the two largest Brazilian steelmakers, also missed first-quarter analyst estimates amid a global steel glut.