Tenaris (TS) reported Q2 earnings late Wednesday of $0.95 per American depository share, down from $0.99 a year earlier.
Four analysts polled by FactSet expected $0.83.
Revenue in the three months ended June 30 fell to $2.97 billion from $3.09 billion a year earlier.
Analysts expected $2.93 billion.
Tenaris shares fell 5.5% in after-hours trading.