Saudi Aramco IPO: Key facts about the oil colossus' history and operations

Aramco, as Saudi Arabian Oil Co is usually known, is set to add another superlative to the list: the world's most valuable listed company.

The sprawling state-owned oil giant announced on Sunday its intention to float on the Riyadh stock market, saying the percentage of shares to be sold would be determined at the end of the book-building period.

Sources have said Aramco could offer 1%-2% of its shares on the local bourse, raising as much as $20 billion-$40 billion.

Aramco is the world's largest oil producer, pumping 10% of the world's supply, and its most profitable. Weaker oil prices cut the company's