(Sharecast News) - London stocks were set to fall at the open on Wednesday amid renewed hostilities between the US and Iran.

The FTSE 100 was called to open around 40 points lower. At 0725 BST, Brent crude was up 1% at $95.56 a barrel and West Texas Intermediate was 0.6% higher at $90.75 after the US launched a new series of strikes against Iranian targets and as Donald Trump warned Tehran against retaliatory strikes.

In a post on Truth Social, the US President said: "The United States is, as we speak, striking Iranian Targets near the Strait of Hormuz. The strikes are large and powerful, and in retaliation for the Iranians' failed attempt at adding sea mines to the Strait, which currently has no mines (They have been completely removed or detonated!), and the Iranians shooting eight missiles, all successfully knocked down, at our Military Base in Jordan.

"If the failed Nation of Iran retaliates for this very justified attack, they will be hit again at a much harder and higher level, but it will not be the biggest attack of them all, that is waiting in the wings and, when it is over, there will be very little left of the Islamic Republic of Iran!"

In corporate news, oil giant BP announced that Ian Tyler has been appointed chairman, taking up the role immediately following an extensive search that considered both internal and external candidates.

Tyler joined the board as a non‑executive director in April 2025 and became interim chair in May 2026.

Halma said it has agreed to acquire Pyxis, a US‑based specialist in water‑quality monitoring technology, in a deal worth an initial $170m (£126m).

The FTSE‑100 firm added that further earn‑out payments of up to $30m may be made depending on Pyxis' performance over the next two financial years.

Pyxis designs sensors and systems used across industrial, municipal and environmental applications, and will operate as a standalone business within Halma's Environmental & Analysis division.