The delay comes at a time of strong activity in the wider market, with bids for other projects in Oman and UAE due in May.
One of the potential bidders, Saudi Masader, confirms it has requested a deadline extension, but would not say why.
Bids for the Ras al-Zour IWPP are now due on 2 June instead of 4 May. The deadline had already been extended from 10 February.
Four groups are understood to be in the running for the deal. They are Japan’s Marubeni Corporation with Belgium’s Suez Energy International; Japan’s Sumitomo Corporation and Malaysia’s Malakoff Berhad; Saudi Masader with Taiwan Power Company, Taiwan Cogeneration Company and Taiwan Water Company; and the local Acwa Power Projects with Korea’s Electric Power Corporation.