Oil major Saudi Aramco said it will be ready for an initial public offering in the second half of 2018 and the work is ongoing.

The company said venue and the timing will depend on the government, adding the listing is a very complex process since Aramco’s size is something that requires time.

 Saudi Arabia is planning to list up to 5 percent of Saudi Aramco in the offering. A successful IPO could give the company a total valuation of up to $2 trillion, making it the world’s biggest oil company by market capitalization.

Saudi Ministry of Energy said last week that the company could be floated either domestically or internationally late this year.