DUBAI/LONDON—Saudi Aramco's board is set to meet this week in Saudi Arabia where it will approve a bond issuance plan that could help finance the potential acquisition of a stake in Saudi petrochemicals maker SABIC, industry sources said. Aramco, the world's top oil producer, plans to issue its first international bonds in the second quarter of 2019 and the issuance will probably be around $10 billion, Saudi Energy Minister Khalid al-Falih has said. The company's representatives are expected to meet fixed-income investors in a bond roadshow in April, two sources familiar with the matter said. The deal is expected to involve the purchase of all, or nearly all, of the 70% stake in SABIC held by the Public Investment Fund, the kingdom's top sovereign wealth fund. That implies a deal value of roughly $70 billion, though the acquisition price has not been made public yet.