Saudi Aramco’s listing is unlikely to go ahead this year, according to British officials who have been warned by their Saudi counterparts that the world’s biggest flotation was expected to be delayed.  Several people briefed on the talks said London still had a good chance of securing the listing, which Riyadh said could value the state energy company at $2tn, but any foreign flotation was likely to happen in 2019 at the earliest. Saudi Arabia wants to sell 5 percent of the world’s largest oil-producing company as part of an economic reform programme driven by Mohammed bin Salman, the crown prince, who visited the UK this week.

The kingdom had targeted a late 2018 listing, with shares to be sold on Saudi Arabia’s Tadawul exchange. But preparedness for the offering and willingness for a simultaneous or sequential flotation on a foreign exchange has been questioned. Delays on IPO decision-making come as advisers have struggled to achieve the $2tn valuation that Prince Mohammed wants. Saudi Aramco’s finances and internal operations have been shrouded in secrecy for decades and its close relationship with the state has raised financial, legal and regulatory challenges.