A Saudi Aramco employee sits in the area of its stand at the Middle East Petrotech 2016, an exhibition and conference for the refining and petrochemical industries, in Manama, Bahrain on September 27, 2016. Photo: Reuters

Saudi Arabia is preparing contingency plans for a possible delay to the initial public offering of its state-owned oil company by a few months into 2019, according to people familiar with the matter.

While the government is still aiming for a Saudi Aramco IPO in the second half of next year, that timetable is increasingly tight for what’s likely to be the biggest share sale in history, the people said, asking not to be named discussing internal deliberations.

Saudi Aramco said in statement the IPO “remains on track. The IPO process is well underway and Saudi Aramco remains focused on ensuring that all IPO related work is completed to the very highest standards on time.” It didn’t give a time frame. The comment was echoed by a Saudi government source Wednesday. Officials have previously said the most likely schedule is the second half of next year.

Several important decisions on the IPO have yet to be taken, stretching the ability…