Lyondell Chemical filed for bankruptcy protection in the US citing waning demand for its products and asked for court approval of an $8 billion loan to help fund operations while it reorganizes.

The Chapter 11 filing on Tuesday was precipitated by a "dramatic softening in demand" as well as "unprecedented volatility in raw materials costs," parent LyondellBasell Industries AF said in a statement. Chemical makers including DuPont Co and Dow Chemical Co have been closing plants and cutting jobs as the global financial crisis curbs demand.

Lyondell Chemical listed $27.1 billion of assets and $19.3 billion of liabilities in the filing. LyondellBasell, one of the world's largest closely held chemical makers, is saddled with at least $25 billion in debt.