Business sources say the Saudis are expected to make shares available for 1% or 2% of the firm.
"This is [a] transformational and historic moment for Saudi Aramco", Amin H. Nasser, President and CEO of Aramco, said in an online statement which praised the company's "disciplined financial approach and prudent and flexible balance sheet".
September 9, 2019 Saudi Arabia plans to list 1 per cent of Saudi Aramco on the Riyadh stock exchange before the end of 2019 and another 1 per cent in 2020, sources tell Reuters.
More than three years after the IPO was first mooted, Aramco published a so-called intention to float on Sunday, the most dramatic change to the Saudi oil industry since the company was nationalized in the 1970s.
Confirmation of the sale of shares in Aramco occurs amid growing concerns about instability in the Gulf region, including the September 14 attack on the facilities of the oil giants that halved their oil production. The strike was quickly blamed on Iran although it vehemently denied any involvement.
"I think this is the right time for us", he said, adding that the percentage of worldwide investors compared with local ones is still to be determined.
With all that in mind, some investors may not want their pension funds to buy shares of Aramco stock.
Aramco, which pumps about 10% of the world's oil, generated the most profit of any corporation previous year with net income of US$111 billion - more than Apple Inc, Google's parent Alphabet Inc and Exxon Mobil Corp combined.
"It's essentially the world's largest unquoted company; it's a massive global oil producer", said David Hunter, director of market studies at Schneider Electric.
Aramco had initially been anticipated to promote a complete of 5% on two exchanges, with a primary itemizing of two% on the Tadawul Saudi bourse adopted by a 3% itemizing on an overseas alternate.
Between 1973 and 1980, Saudi Arabia bought the whole company.
Aramco booked a staggering $111 billion in profit past year, more than what five of its biggest rivals - Exxon, Chevron, Royal Dutch Shell, BP and Total SA - earned together.
Saudi Aramco traces its roots to 1933 when a deal was struck between Saudi Arabia and the Standard Oil Company of California, which later became Chevron, to survey and drill for oil, creating a new firm to do so.
The firm said it has no current plans for a foreign share listing, saying long-discussed plans for a two-stage IPO including an offering on a foreign exchange had been put aside for now.
The pre-IPO research reports, which the banks use to drum up interest on share sales, suggest that Saudi Arabia may fail to achieve the $2 trillion valuation that Saudi Crown Prince Mohammed bin Salman has publicly desired over the last three years.
"It is a colossal public offering that could potentially generate more than 10 years' worth of proceeds raised through IPOs in the country", said Salah Shamma, head of investment at Franklin Templeton Investments.
Aramco said that, effective January 1 2020, it will adopt a progressive royalty scheme, with a marginal rate set at 15% up to $70 per barrel, 45% between $70 and $100, and 80% if the price rises higher.
Aramco said the IPO timetable was delayed because it began a process to acquire a 70 per cent stake in petrochemicals maker Saudi Basic Industries.
The bond sale in April forced the secretive company to reveal its finances for the first time, including net income of $111 billion - more than a third bigger than the combined net income of the five super oil majors.
"As the process has been delayed repeatedly and built up as such an integral component of the crown prince's plan to transform Saudi Arabia, global investors will pay very close attention to how Aramco performs on the domestic exchange", Ulrichsen told AFP.