DUBAI, Oct 15 (Reuters) - Shares in Saudi Arabian petrochemical manufacturer Saudi Kayan tumbled on Thursday after it swung to a third-quarter loss, pulling down the kingdom's index.
Most Middle East bourses - apart from in Saudi Arabia and Qatar - were closed for Islamic New Year. Trade was muted ahead of the weekend there, with renewed weakness in oil prices adding to the cautious mood among investors.
Shares in Saudi Kayan, an affiliate of Saudi Basic Industries Corp (SABIC), fell 9.8 percent after announcing a quarterly loss of 13.8 million riyals ($3.7 million) in the three months to Sept 30. That compares with a profit of 66.9 million riyals in the same period a year earlier.
Saudi petrochemical producers benefit from subsidised feedstock while product prices are linked to oil; the sustained slump in crude prices has hurt their margins.
SABIC fell 1.7 percent, as four of Saudi's five largest stocks declined. Al Rajhi Bank was the exception, ending flat.
The main benchmark index dropped 1.1 percent to 7,699 points, taking its losses to 15.3 percent in the second half of 2015.
In Qatar, property developer Mazaya Qatar fell 3.1 percent after saying it may increase its capital; it gave no further details.
Mazaya accounted for more nearly half of shares changing hands on Doha's index, which rose 0.1 percent.
The telecom sector, seen as a defensive play when energy prices are volatile, was the main support with operators Ooredoo and Vodafone Qatar gaining 1.6 and 1.2 percent respectively.
* The index fell 1.1 percent to 7,699 points.
* The index rose 0.1 percent to 11,772 points. (Reporting by Matt Smith; Editing by Pravin Char)