The firm made a net loss of SR1.26 billion ($334.9 million; Dh1.2 billion) in 2008 down from SR443 million in 2007, the firm, also known as Rabigh Refining and Petrochemical Co, said in a statement posted on the bourse's website.
Profits were hit by delays in starting production at several new petrochemical plants and refinery units, in addition to losses from "a decline in both the prices of and global demand on oil products", it said.
The firm plans to start commercial production before the end of March despite poor global demand, Chief Financial Officer Toshiki Matsumura told Reuters earlier this month.
Last September, PetroRabigh said it would defer by three months the commercial launch of operations at its $10.3 billion (Dh38 billion) refining and petrochemical plant to the first quarter of 2009.
PetroRabigh started partial operation of its facilities in the fourth quarter of 2008.
Aramco and Sumitomo Chemicals paired up in 2005 to upgrade a 400,000 barrel per day (bpd) oil refinery and add a petrochemical complex.