Saudi Arabia's ethylene and propylene capacities will rise to 16.52 million tpa and 6.55 million tpa respectively, with Saudi Kayan's commercial operation in 2011 set to contribute most to the increase, according to BMI's latest Saudi Arabia Petrochemicals Report. Compared with 2010, total PE capacity will rise 20 percent to 8.86 million tpa, PP will rise 11 percent and PS, PET and PVC capacities will remain unchanged. Ethylene capacity in 2015 is forecast to be more than double that of 2008 levels, with Jubail and Yanbu the focus of petrochemicals developments. BMI further said technical problems at Sahara Petrochemicals' Al-Waha plant and at Petro Rabigh have adversely affected PP output. However, the temporary closures did not affect supplies, which were maintained through inventories, although BMI expected a negative impact on profitability at the respective plants. On the upside, NatPet resumed operations at its Yanbu-based 400,000tpa PP complex after completing a scheduled maintenance 11 days before the 60-day turnaround was due to be completed. JVs are being established to build and operate units aligned with Saudi Arabia's National Industrial Clusters Development Program, which aims to expand and diversify its manufacturing sector and create opportunities in downstream industries such as construction, automotive, electronics, medical technologies and appliances. SABIC also seeks to use its basic petrochemicals projects as raw material for processing. The decision by Dow Chemical and Aramco to go ahead with the integrated $20 billion Sadara Chemical Company JV complex will significantly boost downstream chemicals growth.