According to a recent report on Reuters, Saudi Aramco’s decision to put off its listing was driven by the need to get more key investors on board. The world’s largest oil company was pushing ahead with plans to list 1-2% of its stake on a Riyadh-based stock exchange to raise around $20 billion in capital.

However, the drone attacks on Aramco’s crude processing facilities at Abqaiq and Khurais in mid-September caused the company to consider delaying its IPO plans as the focus shifted to resuming full capacity and allaying investors’ concerns on safety. However, according to sources, ongoing concerns around the valuation has kept marquee backers away from coming on board with the company’s plans.

According to initial plans, Saudi Aramco’s IPO was expected to launch on October 20, but banks involved in the listing were informed of the company’s decision to delay it late last week. The initial reasoning suggested waiting for Q3 earnings results to boost investor confidence after the attacks.

Key investors like international money managers still seem hesitant to back Aramco’s IPO plans. Saudi Aramco has not offered any official comment on the issue yet but is expected to make a formal announcement in the coming weeks.