Shares in Serica Energy nosedived after the firm said it was “evaluating the implications” of Donald Trump’s decision to pull the US out of the Iran nuclear deal.
UK-based Serica agreed to buy 50% of the North Sea Rhum field from BP last year. The transaction was effective from January 1 and is expected to close mid-2018.
The field is 50% owned by the Iranian Oil Company (UK).
A Serica spokesman said: “The Company is evaluating the implications of these statements and how they relate to the Rhum field in which the Iranian Oil Company (UK) is a 50% partner. We will update the market, as appropriate, in due course.”
Shares in London sank 9.18% to 73.20p in early trading.
Production at Rhum, 240 miles north-east of Aberdeen, was suspended in 2010 when Europe imposed sanctions on Iran over its nuclear programme.
Work only resumed four years later after the UK agreed to set up a temporary management scheme whereby all revenue due to Tehran would be held until sanctions were lifted.
Following the removal of European Union and United Nations sanctions on Iran in January 2016, the temporary management scheme ceased.
Iran regained control of its stake and in September 2016 BP obtained a licence from the US Treasury, through its sanctions enforcement arm, the Office of Foreign Asset Control, to continue operations at the field.