Kingdom, owned by Saudi billionaire and Citigroup (C.N) investor Prince Alwaleed bin Talal, made a non-binding offer on Jan. 31 for Zain's 25 percent stake in Zain Saudi. The offer was due to expire on Feb. 13.

"The firm has agreed to extend the offer for the second time until 5 p.m. time on Wednesday, February 16 and that is according to the request of the board of Kuwait's Zain," Kingdom Holding said in a bourse statement on Sunday.

Zain must sell its Saudi assets to clear the way for the UAE's Etisalat to complete its $12 billion bid for a controlling 46 percent stake in Zain.

Kingdom did not say what it would pay to buy the stake.