Following a long delay, Saudi Arabia has authorized the sale of the state-owned oil company Aramco. It will be the biggest stock market flotation in history and the market debut could value Saudi Aramco at $1.5 trillion, significantly below initial expectations of up to $2 trillion.

Nevertheless, Aramco’s initial public offering will be the biggest in history, raising $40bn-$45 billion, surpassing the record $25 billion raised by China’s tech firm Alibaba in 2015. The precise details of the offer won’t be released until November 9th.

Only a small portion of shares will be released on to the Riyadh market, likely to be in the range of 1% to 3% of the total stock, according to estimations. The size and scale of Aramco are likely to require the financial liquidity only available on the globe’s biggest exchanges, such as Wall Street or London.

Apple is now the world’s most valuable company, surpassing Microsoft last Friday. Apple’s stock has surged in recent weeks as numerous analysts have predicted better-than-expected iPhone 11 sales. Many firms had anticipated that people would skip out on Apple’s latest phone lineup to wait for iPhones released in 2020.

Yasir al-Rumayyan, the chairman of Saudi Aramco, said: “Today marks a significant milestone in the history of the company and important progress towards delivering Saudi Vision 2030, the kingdom’s blueprint for sustained economic diversification and growth.”

The company is responsible for 13% of the world’s oil, and this year it revealed half-year profits of $46.9 billion – more than the next six biggest oil companies combined. Saudi Arabia is expected to use the listing to leverage its vast fossil fuel reserves to help modernize its economy and gain international acceptance.

The sale of the state-owned company is controversial among environmentalists and campaigners pushing to keep fossil fuels from being burned. A recent report showed Aramco has been responsible for 4.38% of the world’s carbon emissions since 1965 and named it as the biggest corporate polluter in the world.

Green groups say the company’s IPO undermines global efforts to tackle the climate crisis. Aramco counters with data that a spokesperson said showed that it had the smallest carbon footprint of any of the oil majors per unit of output.

The company “lifts” 11.6m barrels of oil every day and has reserves of 227 million barrels. It costs just $2.80 for the company to lift each barrel of oil, compared with the $62 price per barrel on world markets, resulting in vast profits. It said its operating cash flow in 2018 was $121 billion and it would pay out dividend’s worth $75 billion this year.

The Saudi government said it would forego its share of dividends in the event of an oil price collapse, effectively creating a company that guarantees dividends of $75 billion a year. The documents also reveal that the drone attack on Aramco’s facilities in September cost it $28 million, a sum that is so insignificant to the company’s scale that it was not material to the accounts.