SAO PAULO, May 4 (Reuters) - Brazilian steelmaker Companhia Siderurgica Nacional (CSN) posted first-quarter net income of 1.36 billion reais ($277.3 million) on Wednesday, down 76% from the same period the previous year.

The bottom line came in below the 3 billion reais expected by analysts polled by Refinitiv.

The company said the first three months of 2022 were "marked by a challenging scenario" due to heavy rain in Brazil's Southeast region and cost pressures on coal and coal coke.

On a sequential basis, however, the company posted a 29% jump in net income driven by higher realized iron ore prices that boosted its mining unit.

Adjusted earnings before interest, taxes, depreciation, and amortization (EBITDA) fell 19% from the previous year to 4.71 billion reais, also led by mining division CSN Mineracao SA .

CSN said steel and iron ore sale volume fell by 12% and 16% respectively from the first quarter of 2021.

($1 = 4.9198 reais) (Reporting by Gabriel Araujo and Peter; Editing by Stephen Coates Frontini; Editing by Jacqueline Wong)