The company, a yardstick for rivals such as Dow Chemical and Germany's BASF, posted net profit of SR5.81 billion ($1.55 billion), compared with SR4.58 billion in the fourth quarter of 2009 and an average analyst forecast of SR5.87 billion.

Last year, SABIC benefited from higher production after adding new capacity under its Saudi-based affiliates Yansab and Sharq and under its Tianjin joint venture with Sinopec.

Its 42.9-percent owned Saudi Arabian Fertilizers Co. (SAFCO) said on Sunday its fourth-quarter net profit tripled to SR1 billion.

"Yansab and SAFCO made profits and (this) is a main reason behind SABIC's improved results," said Hesham Abo-Jamee, chief investment officer at Riyadh-based Bakheet Investment Group.

"The rise in fourth-quarter profit ... is due to an improvement in prices in most of the petrochemical and plastics products as well as better operational performance," SABIC said in a bourse statement.

Fourth-quarter operating profit rose 29 percent to SR10 billion.

Abo-Jamee said SABIC was expected to make between SR24 billion and SR25 billion in profit for 2011.

High oil prices are positive for petrochemical firms because they increase product prices. SABIC usually beats rivals on profitability because it buys feedstock at lower prices.

Profits in 2011 for Yansab and SAFCO are seen at SR2.4 billion and SR3.5 billion respectively, Abo-Jamee said.

He said Kayan Petrochemicals Co., a 35-percent owned unit of the petrochemicals giant would also help SABIC as it is expected to have an output capacity of 70 percent this year at its mega complex in Jubail, on the Gulf coast.