Saudi Arabia's Yanbu National Petrochemical Company (Yansab) beat analysts' forecasts on Thursday despite reporting a 36.4 percent drop in fourth-quarter net profit as lower product prices dragged earnings.

The firm, a subsidiary of Saudi Basic Industries Corp (Sabic), made a net profit of SR393.1 million  ($104.9 million) in the three months to December 31, down from SR617.8 million in the same period of 2014, it said in a bourse filing.

Three analysts polled by Reuters on average forecast Yansab would make a quarterly profit of SR345.8 million.

It is the fourth straight quarter in which Yansab has reported falling profits. It had already announced it was trimming its dividend payout for the second half of 2015, having cut it in the first half of the year as well.

Yansab said lower average sales prices for all of its products eliminated the benefits from higher sales volumes, causing the profit drop. It did not elaborate further.

Saudi companies issue brief earnings statements early in the reporting period before publishing more detailed results later.

Like many petrochemical firms in the kingdom, Yansab's earnings have been hit hard by falling product prices as they are closely tied to the price of oil, which is languishing at 12-year lows. Saudi producers have also benefited from subsidised energy and feedstock costs, so lower crude prices compress their profit margins. - Reuters