Saudi Arabian shares ended lower on Thursday as investors shunned stocks across the board amid tumbling oil prices, while heavyweight Industries Qatar weighed on the benchmark.

Oil prices fell 4% to their lowest since mid-June, extending the previous day's sharp decline on the potential impact that renewed coronavirus lockdowns will have on oil demand.

December Brent crude futures were down $1.90, or 4.9%, at $37.22 by 1236 GMT.

The kingdom's benchmark index declined 2.7%, with petrochemical firm Saudi Basic Industries sliding 3% and National Commercial Bank 1180.SE shedding 3.3%

Elsewhere, oil giant Saudi Aramco retreated 1.5%.

The Organization of the Petroleum Exporting Countries (OPEC) and its allies will have to contend with a "lot of demand issues" before raising supply in January 2021, given throughput cuts by oil refiners, the head of Saudi Aramco's trading arm said. 

Lower prices and disruptions to crude exports could affect the fiscal balances of countries reliant on oil income.

In Qatar, the index dropped 1.4%, with petrochemical firm Industries Qatar declining 3.6%.

The company earlier this week had reported a net profit of 951 million riyals ($261.26 million) for the first nine months of 2020, down from 2 billion riyals a year earlier.

Most markets in the Middle were closed for a public holiday.

SAUDI ARABIA slid 2.7% to 7,908 points QATAR fell 1.4% to 9,691 points

($1 = 3.6400 Qatar riyals)

(Reporting by Ateeq Shariff in Bengaluru, Editing by William Maclean) ((AteeqUr.Shariff@thomsonreuters.com; +918061822788;))