One of Saudi Arabia’s top financial regulators has warned the listing of the country’s state oil firm Aramco, which is set to become the biggest initial public offering (IPO) in history, will carry great execution risk.

Mohammed El-Kuwaiz, chairman of the Saudi Arabian Capital Market Authority, told CNBC Friday: “The main risks are around execution. Whenever you have something which has this high an aspiration level, and this tight a timeline, the challenge is to get it done and get it done with the right level of quality.”

His comments come in the wake of a Bloomberg report suggesting the Aramco IPO could be pushed back to 2019 due to the large amount of preparatory work that still needs to be completed ahead of the listing. Aramco hit back at the claim, stating the IPO “remains on track”.

The Saudi government is yet to announce whether Aramco’s primary listing will be in London or New York, but it has decided that…