Aramco declined to comment.
It is expected to release more details about the company in an IPO prospectus document later on Saturday.
Assuming Aramco achieves a total valuation of $2 trillion, the retail tranche could be worth around $10 billion, the sources said on Saturday.
Aramco fired the starting gun on the domestic IPO last week after a series of false starts. It did not give details on how much would be sold, or when the listing would happen, while expert valuations vary from $1.2 to $2.3 trillion.
A government committee has met in the past few months with dozens of wealthy Saudi individuals to secure pre-sale agreements, sources told Reuters last month.
And the government has encouraged investors to repatriate cash held overseas to buy into the IPO to avoid draining too much liquidity from the Saudi banking system, they said.
Reuters reported on Oct. 17 that Aramco can take advantage of new market rules that allow issuers the flexibility to sell more shares to retail investors, likely exceeding the usual 10% seen in recent IPOs.
“Local demand is strong,” a second source said on Saturday, adding that this would lead institutional investors to think that up to 75% of the IPO would be available for them.
(Editing by Alexander Smith)