Global iron ore giant Vale SA reported disappointing first-quarter results, as operational pressures outweighed the benefits from rising prices and sales volume. According to documents released on Tuesday, the company's adjusted earnings before interest, taxes, depreciation, and amortization reached $3.9 billion, falling short of the $4.1 billion average estimate from analysts. Vale attributed the weaker performance to the strengthening Brazilian real and increased operational expenses. The firm now anticipates that the cash cost of iron ore production will hit the upper end of its annual forecast range of $20 to $21.50 per ton, citing factors such as rising oil prices. Vale's American depositary receipts declined by as much as 1.8% in after-hours trading.