DUBAI  - Saudi Aramco is seeking advisers to arrange debt financing needed for the acquisition of a stake in Saudi Arabian Basic Industries Corp (SABIC), banking sources familiar with the matter said on Thursday.

The Saudi oil giant could borrow as much as $50 billion from international investors to fund the acquisition, sources previously told Reuters.

A request for proposals was sent out on Wednesday and banks are expected to submit proposals for the financing by Monday, one of the sources said.

Aramco did not immediately respond to a request for comment.

The world’s top oil producer plans to issue its first international bonds in the second quarter of 2019, likely worth about $10 billion, Saudi Energy Minister Khalid al-Falih said this month. The bond issuance could help finance the SABIC acquisition.

Aramco is looking for advisers for both an international bond issue and bank financing, said one of the sources.

The debt is needed to back the purchase of all, or nearly all, of the 70 percent stake in SABIC held by the Public Investment Fund (PIF), the kingdom’s top sovereign wealth fund.

That implies a deal value of roughly $70 billion.

Aramco is working with JP Morgan and Morgan Stanley on the stake purchase, sources previously told Reuters.

The two banks, along with others, were working on the planned stock market listing of Aramco before the move was put on hold. Aramco’s new planned listing date is 2021, Saudi officials have said.

(Reporting by Davide Barbuscia and Hadeel Al Sayegh. Editing by Jane Merriman and Mark Potter) ((Davide.Barbuscia@thomsonreuters.com; +971522604297; Reuters Messaging: davide.barbuscia.reuters.com@reuters.net))