(Updates to add S&P comments, background)
SYDNEY, May 13 (Reuters) - Origin Energy ORG.AX has appointed Macquarie Capital MQG.AX to advise on a potential spin-off of Origin's gas production businesses, including its $25 billion liquefied natural gas plant, two sources familiar with the matter said on Friday.
Australia's largest energy retailer believes shareholders receive little benefit from owning an integrated business which includes a stake in debt-saddled Australia Pacific LNG, power plants and a power and gas retail business, one source said.
The spin-off would shift debt to the gas production business and help protect Origin's investment-grade credit rating, which is currently one notch above junk, the source said.
Any spin-off of the gas business should only occur after APLNG is in full production, expected later in 2017, according to the source.
Both sources declined to be named as the matter was confidential. Origin and Macquarie declined to comment.
To help cut net debt to $9.3 billion, Origin last year raised A$2.5 billion ($1.83 billion) in a sale of new shares and sold its stake in New Zealand's Contact Energy, as weak oil prices dented the outlook for its LNG project. shares are down 1 percent in early deals in a flat broader market.
Shareholders and ratings agencies Moody's and Standard & Poor's are likely to see potential benefits of a spin-off, depending on how it would be executed.
Origin's debt can largely be serviced by its retail and power generation businesses following the capital raising, S&P senior director Thomas Jacquot said.
It is also planning to raise an additional A$800 million through some asset sales but has been forced to push back the deadline to June 2017 from this year, according to sources.
($1 = 1.3667 Australian dollars)