Aramco has revived a planned upgrade of the Ras Tanura refinery, put on ice with the oil price collapse. But contractors will have to live with tighter margins.

State petroleum giant Saudi Aramco has issued a new tender for two engineering, procurement and construction packages (EPC) to upgrade its Ras Tanura refinery, having put bidding on hold early last year, as the collapse in crude prices since mid-2014 tightened the screw on spending plans.

Contractors have been asked to submit new...