Saudi Arabia is planning a two-part listing of Saudi Arabian Oil Co. on its domestic stock market to ensure that the exchange can easily absorb what would be the kingdom’s largest initial public offering, according to advisers familiar with the process.

Aramco, as the national oil giant is usually known, is considering a 1% offering of the company this year and another 1% next year on the local market,  the advisers said, as the government seeks to accelerate a centerpiece of Crown Prince Mohammed bin Salman’s economic reform program.

The crown prince aims to list 5% of Aramco in an effort to raise billions of dollars to diversify his oil-dependent economy. He has indicated he wants a $2 trillion valuation for the world’s most profitable oil company — though analysts put the company’s value at closer to $1.5 trillion.

Even at the lower estimate, a 1% sale is likely to raise $15 billion from Saudi and international investors and would be the largest initial public offering on the $500 billion domestic market, known as the Tadawul. Saudi Arabia opened up its domestic market in 2015 to institutional foreign investors, who can participate in IPOs.

The offering will commence “very soon,” Aramco President and Chief Executive Amin Nasser told reporters at the World Energy Congress in Abu Dhabi on Tuesday. He said the company was prepared to list in multiple markets: “The primary listing is to list locally, but we are also ready for listing outside in other jurisdictions.”

An expanded version of this report appears on WSJ.com.

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