The Saudi Arabian stock market could not sustain its positive momentum from Saturday, as WTI oil prices may head lower later this week, possibly moving back toward $77, research firm CPM Group says. Petrochemical leader Sabic ended flat at $88.25. "Last week crude oil fell after EIA data revealed United States crude oil inventories had unexpectedly increased 360,000 barrels. Later in the week crude oil rose toward $80 on concerns over adverse weather conditions possibly disrupting offshore oil production in the Gulf of Mexico", CPM research writes. Nevertheless, the Saudi economy strengthened. According to Amman-based Jordinvest, non-oil Exports in Saudi Arabia surged by 39% to SR11.9bn ($3.2bn) in May 2010 compared with SR8.5bn ($2.3bn) in May 2009. Saudi Arabia's main non-oil exports were plastics, petrochemicals and metals comprising 32% of the total non-oil exports.