Saudi Arabia has abandoned plans for a stock market listing of its state-owned oil colossus, Aramco, in a setback for crown prince Mohammed bin Salman's push for reform.
The group of bankers assembled for what would have been the biggest ever float has been disbanded without fanfare.
The budget for financial advisers, which included JP Morgan, Morgan Stanley and HSBC, who were called in to assist with the deal, has not been renewed since June, Reuters reported.
The decision raises questions for City authorities who relaxed Britain's listing rules in an attempt to attract Aramco to the London market in competition with New York and Hong Kong.
The Financial Conduct Authority created a new category for sovereign-controlled companies under its "premium" umbrella, despite opposition from business groups and investors.
The Institute of Directors said it was "deeply disappointed" by the move, which it claimed marked a "reduction in standards" for corporate governance.
The Government offered a US$2 billion ($2.9b) loan to try to secure the deal.
Saudi Arabia announced plans to float around 5 per cent of Aramco in 2016 worth as much as US$100b, as the centrepiece of the young crown prince's attempts to liberalise the kingdom and build economic ties with Western nations.
At the time, it was predicted that a listing would value Aramco at more than US$2 trillion, although the figure has since been disputed by analysts as too high.
The crown prince embarked on a tour of potential listing venues as governments and financial authorities rolled out the red carpet.
President Trump tweeted last November that he "would very much appreciate Saudi Arabia doing their IPO of Aramco with the New York Stock Exchange".
As recently as March, the Saudi energy minister said that London remained in contention and Aramco's annual report released this month said preparations for the "landmark event" were continuing.
However, a Saudi source familiar with the plans said: "The decision to call off the IPO was taken some time ago, but no one can disclose this, so statements are gradually going that way - first delay, then calling off."
A senior financial adviser said: "The message we have been given is that the IPO has been called off for the foreseeable future."
The crown prince has pursued a range of investment plans as part of a so-called Vision 2030, a bid to turn the country into a global investment powerhouse and reduce its dependence on demand for oil.
The expected proceeds of an Aramco float were viewed as a key pillar of the plan.
Aramco is now focused on the purchase of a "strategic stake" in petrochemicals maker Saudi Basic Industries Corp from the Saudi sovereign wealth fund PIF.
It has held talks with the entrepreneur Elon Musk over a potential US$82b buyout of the electric carmaker Tesla, but doubts have mounted in recent days. PIF is said to be considering a smaller investment of just US$1b in Lucid Motors, a carmaking rival set up by former Tesla engineers.
The crown prince's attempt to build international links suffered another blow this month when a diplomatic row with Canada spilt over into the financial markets. Canadian assets were sold off by Saudi-backed funds following criticism of the treatment of human rights activists in the kingdom.
Some analysts believe the sell-off has damaged the kingdom's standing as a potential investment hub.