The Calouste Gulbenkian Foundation, a Portuguese charity, may sell Partex Oil and Gas (Holdings) Corp. to CEFC China Energy Co. Ltd of Shanghai, Reuters reports.

The news agency says the foundation issued a written statement disclosing that a company had offered to buy Partex, without identifying the prospective buyer.

Reuters identifies the prospective buyer as CEFC China Energy, and says the Chinese company may pay €500 million (US$622.67 million) for 100 percent of Partex.

Partex has stakes in oilfields in Brazil and Oman.

Calouste Gulbenkian Foundation said it was negotiating a sale.

“After an analysis of all the conditions, a decision will be taken in the defence of the best interests of the foundation,” Reuters quotes the foundation as saying.