Saudi Arabia is negotiating commitments from its wealthiest citizens to buy stock in the Aramco initial public offering, from the Olayan family and Prince Alwaleed Bin Talal to low-profile tycoons in the oil producer’s backyard, people with knowledge of the matter said.

The billionaire Olayans, who own a major stake in Credit Suisse Group, are considering buying several hundred million US dollars worth of Aramco shares, according to the people.

Prince Alwaleed has also held talks to commit a significant amount to the IPO, the people said, asking not to be identified because the information is private.

Aramco representatives have also been seeking an investment from the Almajdouie family, whose businesses range from distributing Hyundai Motor vehicles in the kingdom to a large logistics operation, the people said. They have also approached members of the Al-Turki clan, who are involved in fields from real estate to general trading, food distribution and ports, the people said.

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Saudi Arabia is turning to rich local families, some of whom had members detained in Riyadh’s Ritz-Carlton hotel during a 2017 corruption crackdown, as it seeks to shore up demand for the record-breaking share sale.

Some control sprawling groups of companies, and it wasn’t immediately clear which vehicles they would use to buy the stock or if certain individuals would invest their personal fortunes.

There’s no certainty the wealthy investors will place orders, and precise commitments could vary based on the final valuation decided by Aramco, the people said. Saudi Crown Prince Mohammed Bin Salman has long insisted the state oil company is worth $2 trillion, a figure that many Western fund managers have balked at, Bloomberg News has reported.

Aramco declined to comment. Representatives for Olayan Group and Alwaleed’s publicly listed investment company, Kingdom Holding Co, didn’t respond to requests for comment. Repeated calls to Nesma Holding Co, a conglomerate controlled by one branch of the Al-Turki family, and Almajdouie Group weren’t answered.

Almajdouie Group is based in the Eastern province capital of Dammam, a stone’s throw from Aramco headquarters in the desert city of Dhahran. Its transportation affiliates have hauled oil pipes and drilling rigs to Aramco work sites, according to their websites. The company’s bakery business has also been an Aramco supplier.

Nesma, headquartered in the port city of Jeddah on the Red Sea, owns dozens of companies including an airline, an electric equipment supplier and a hotel operator. The group’s engineering and construction business has done work for Aramco, the oil giant’s website shows.

The Olayans run one of the kingdom’s biggest family-owned conglomerates and have a member sitting on the Morgan Stanley board. Late family patriarch Suliman Olayan began his career with a forerunner of Aramco before later starting a contractor that helped support the construction of a mammoth Aramco pipeline project.

Olayan Group has since grown into a conglomerate that runs Burger King outlets across the Middle East, owns a Coca-Cola bottler and has joint ventures with Colgate-Palmolive Co and Kimberly-Clark Corp.

Alwaleed, known for his overseas holdings in companies from Citigroup to Twitter, was among the billionaires and officials that the government detained in the Ritz in 2017. He was freed in late January 2018 and said he signed an “understanding” with Saudi authorities that left him free to function normally. Since his release Alwaleed has been looking for new investments.