Saudi Basic Industries Corp (SABIC) posted a 12.4 percent profit drop in the fourth quarter from a year earlier, citing lower average selling prices and a decrease in the share of results of associates.

SABIC made a net profit of 3.24 billion riyals ($864 million) in the three months to Dec. 31, down from 3.7 billion riyals in the year-earlier period, the company said in a bourse statement.

That was lower than the average forecasts of three analysts polled by Refinitiv, who expected SABIC to make a net profit of 4.92 billion riyals.

The company's results are closely tied to oil prices and global economic growth because its products - plastics, fertilisers and metals - are used extensively in construction, agriculture, industry and the manufacturing of consumer goods.

Oil prices fell in 2018 for the first time since 2015, after a disappointing fourth quarter that saw buyers flee the market over growing worries about a supply glut and mixed signals related to renewed U.S. sanctions on Iran.

In 2018, U.S. West Texas Intermediate crude (WTI)futures slumped nearly 25 percent, while Brent tumbled more than 19.5 percent.

SABIC's biggest shareholder, the Public Investment Fund, is in talks with Saudi national oil giant Aramco IPO to sell its majority stake in the petrochemicals giant to Aramco.  ($1 = 3.7505 riyals)

(Reporting by Saeed Azhar; Editing by Tom Arnold) ((Saeed.Azhar@thomsonreuters.com; +971 44536787; Reuters Messaging: saeed.azhar.reuters.com@reuters.net))