"Commercial operations at all of the company's (Yansab's) units will start on March 1, 2010," Yansab said in a statement.

Since its inception four years ago, Yansab spent about SR18.9 billion ($5.04 billion) — about SR12.5 billion of which were loans — to build its petrochemical complex, according to its 2009 financial statement. The complex has a total annual production capacity of about 4 million tons, including 900,000 tons of polyethylene, 400,000 tons of polypropylene and 700,000 tons of monoethylene glycol.

SABIC, the world's biggest bulk chemicals company by market value, hopes that affiliates — such as Yansab, Sharq and its joint-venture with China's Sinopec — coupled with demand from China would underpin a profit recovery in 2010.

Mohamed al-Mady, SABIC's chief executive, said in January that Yansab, Sharq and the Tianjin joint-venture with Sinopec would start "at normal production rates" in the first half of 2010, without giving precise details.

It also plans to start Saudi Kayan Petrochemical Co. in the second half of this year — in which SABIC directly holds a 35-percent stake, he added.