Tenaris SA (TS) shares plummeted 6.04% during pre-market trading, as the market reacted negatively to the company's cautious guidance for the second quarter, which overshadowed its better-than-expected first-quarter financial results.

The steel tube manufacturer reported fiscal first-quarter earnings of $1.07 per American depository share, exceeding analyst expectations of $0.89. Revenue for the quarter rose to $3.10 billion from $2.92 billion a year earlier. However, the company stated that its sales for the current quarter will be affected by lower shipments in the Middle East, and margins will be pressured by higher logistics costs and lower absorption of fixed costs.

Adding to the market's concerns was the announcement of a leadership transition. The company appointed Gabriel Podskubka as its new Chief Executive Officer, while Paolo Rocca will continue to serve as Chairman of the Board. Such executive changes often introduce an element of uncertainty as investors assess the new leadership's strategic direction.