State oil giant Saudi Aramco plans to start up the expanded Juaymah gas plant in September - a few months later than scheduled, sources working on the project have announced.
A source told Reuters that "difficulties during the mechanical commissioning caused the delay."
The plant was last scheduled to come online in June, following delays to meet the initial first quarter 2008 deadline.
Aramco is boosting capacity at Juaymah by around 50% to handle increased volumes of petrochemical feedstock ethane and light oils that form when gas is extracted, called natural gas liquids (NGLs).
The expansion at Juaymah will add 260,000 barrels per day (bpd) of additional capacity to the Juaymah plant, taking capacity there to 815,000 bpd.