British gas giant BG Group has agreed to sell its wholly-owned subsidiary in Australia - QCLNG Pipeline Private Limited - to the APA Group for $5 billion.

The company said the deal is expected to be completed in the first half of 2015 and is conditional on the start of commercial LNG deliveries from the QCLNG export facility at Gladstone and on partner consent.

This is the biggest sale by BG since it earlier this year announced plans to look at asset sales across the globe to monetise some of its investments and return cash to shareholders.

BG Group had earlier expected to finalise a roughly $4 billion sale of gas pipelines in Australia's Queensland state by Christmas.

"The sale of the QCLNG pipeline is in line with our strategy to focus on BG Group's core areas of oil and gas exploration and production and LNG," Andrew Gould, interim executive chairman of BG Group, said in a statement.

BG said the transaction is expected to result in a post-tax profit of approximately $2.7 billion. The company also said it expects sale proceeds will be used to reduce net debt and fund future growth.

Many investors and analysts expect BG to ultimately offload parts of its portfolio in Brazil and East Africa.

Major oil producers are under intense scrutiny as they are expected to present cost-cutting strategies to shield earnings from a steep drop in oil prices.(Full Story)

BG had promised to sell assets as part of a broader drive by oil companies to boost cash flows and returns to the shareholders and cut capital investments following cost overruns.

QCLNG Pipeline owns a 543-km-long underground pipeline network that links BG's natural gas fields in southern Queensland to a two-train liquefied natural gas export facility at Gladstone on Australia's east coast.

The company said the pipeline was built between 2011 and 2014 and has a current book value of $1.6 billion.-Reuters