China's $200-billion sovereign wealth fund has added privately-held commodities trader Glencore International AG to its roster of approved investment partners as it deepens its access to global raw material markets, two sources familiar with the matter said.

A source familiar with China Investment Corp's strategy said Glencore and sovereign wealth fund's fixed-income department recently concluded a preliminary "commodities product investment agreement". The source was not able to offer any additional details.

A manager at a trading and investment firm in Asia, which is a client of Glencore, said top management from Glencore visited CIC in Beijing in August and signed a memorandum of understanding in which CIC agreed to invest in Glencore's products or bonds. A CIC spokesman declined to comment.