Saudi Arabia's  benchmark slumped to a fresh 10-week low yesterday as investors fretted that a gloomier outlook for the global economy would lead to lower oil receipts for the worlds top crude exporter .
Other Middle East markets were mixed, with investors cautious as third-quarter earnings season got under way.
The International Monetary Fund cut its growth forecasts for the second time in six months yesterday, warning the global economic slowdown was worsening.
"This will obviously put some pressure on (Saudi Arabia's) petrochemical sector," said Farouk Miah, head of research at NCB Capital. "Fundamentally, there are concerns and added to that are the geopolitical issues that are continuing in the region ." In Bahrain, the measure declined 0.6 per cent to 1,062 points hurt by weak trading in the services and banking sectors.
Saudi's index fell 0.3pc, its fourth decline in five sessions to take its losses since Sept. 15s four-month high to 5.2pc. Oil has fallen 8.7pc over the same period.
The petrochemicals benchmark eased 0.08pc, down 5.5pc for 2012.
Egypt's main index fell 0.4pc to a four-week low, extending losses following Sunday's 2.4pc decline.
In the United Arab Emirates, National Bank of Abu Dhabi (NBAD) rose 0.5pc after it said the UAE central bank had extended a deadline for banks to comply with new lending limits to state-linked companies.
The original deadline was Sept. 30, but commercial banks will now have an extra six months, NBAD said.
Dubai's index rose 0.08pc, but gave back early-session gains. It hit a 23-week closing high on Sunday, but fell 1.1pc the day after.