KUALA LUMPUR/MILAN (REUTERS) - Malaysian state oil firm Petroliam Nasional Bhd is considering selling its majority stake in a US$27 billion (S$36.7 billion) Canadian liquefied natural gas (LNG) plant, three people familiar with the matter said this week.

Petronas, as the company is known, is weighing options for the project as a more than 50 per cent slide in crude oil prices since the middle of 2014 has hit the group's profits and prompted cuts to capital expenditure and jobs.

Amid the cost-cutting, the economics of the Canadian project - which took three years to get approval due to environment concerns - have been called into question as LNG prices LNG-AS have fallen more than 70 per cent in two years.

Petronas was given the go-ahead for the C$36 billion (S$36.7 billion) project by the Canadian government earlier this week. It said then that executives would study the 190 conditions imposed by the authorities and conduct a review before deciding on the next steps.

Petronas said on Friday it will not provide any additional comment when asked about the potential sale.

The sources said Petronas has been considering a sale for months, after it became apparent that a Canadian approval was possible, but had yet to take a final decision. Other options are also being considered, including putting it on ice. "They are going to be looking at gas prices, costs and returns before they make the final decision," said one of the sources. "It is a very tough call."

The Canadian project is Petronas' biggest foreign investment and seen as a sign of Malaysia's global energy ambitions. An exit would underscore the financial constraints at the state-run firm and also the soft outlook for LNG prices.

Last month, Petronas reported an 85 per cent slide in second-quarter profit and labelled the industry outlook "gloomy"well into 2017. It has committed to paying 16 billion ringgit to the government coffers this year, down nearly 40 per cent from its year-ago contribution.