Shares in DNO International, the Norwegian oil company, plunged more than 45 per cent on Thursday as trading resumed in the stock for the first time since Kurdish authorities threatened to cancel its licence to export oil from Iraq.

Helge Eide, chief executive of DNO, told the Financial Times that his company – the first to pump oil in Iraq since the 1970s – was in talks with the Kurdish regional government in a bid to salvage its investment. “We are currently in discussions,” he said. “We are working to resolve [the situation] as soon as possible.”