The company is seeking the cargoes for delivery over late August to September in a tender that closes on June 13 and is valid for a day, one of the sources said.
But limitations on quantity and the delivery period may mean the tender conditions are hard to meet, the second source said.
Guangdong Energy Group could not immediately be reached for comment on the tender.
The utility, previously known as Guangdong Yudean Group, bought its first LNG cargoes totalling 120,000 tonnes from Malaysia's Petronas earlier this year after securing access to a receiving terminal in southern China.
Those cargoes were for delivery in May and July.
A company executive has told Reuters that Guangdong Energy has the right to bring in five cargoes of its own purchase this year. It typically secures gas from China National Offshore Oil Company, or CNOOC, which operates the Guangdong Dapeng LNG terminal in Shenzhen.
Guangdong Energy is a minority investor in CNOOC's Shenzhen LNG import terminal.
LNG imports into China - the world's second-largest buyer after Japan - are dominated by state players CNOOC, PetroChina and Sinopec, which have built most of China's receiving terminals and import globally from exporters such as Qatar, Australia and Russia.
Beijing wants to liberalise the market by encouraging state firms to open terminals to independent companies, but access has so far been rare and costly for smaller players.
The Guangdong Energy Group, a joint venture between the Guangdong provincial government and state utility Huaneng Group, operates 32 gigawatts of mostly coal-powered generating capacity, according to the company website. About 8 percent of its total capacity is fuelled by natural gas, the website says.