BG Group has completed transactions with China National Offshore Oil Corporation for the sale of additional interests in its QCLNG project on Curtis Island for US$1.93 billion.
Under a separate agreement, BG Group will also supply CNOOC with an additional five million tonnes per annum of liquefied natural gas.
At the completion ceremony in Brisbane, BG Group chief executive Chris Finlayson said the sale signalled the start of a new chapter in the partnership.
"Our relationship with CNOOC has grown as they increase their investment in our QCLNG project, and BG Group becomes the largest supplier of LNG to the world's fastest growing energy market," Mr Finlayson said.
"Today's agreements exemplify our strategy to manage our portfolio more actively, monetise assets at different stages in their life cycle and bring in key partners to accelerate value delivery."
BG Group has sold certain interests in upstream coal seam gas tenements in Australia and a further equity stake in the QCLNG project Train 1 liquefaction facility.
CNOOC has acquired a 40% equity interest in QCLNG Train 1, increasing its equity ownership from 10% to 50%.
BG Group and CNOOC will jointly invest in the construction of two LNG ships in China, adding to the two ships already committed under the LNG agreements signed in March 2010, and CNOOC will have the option to participate up to 25% in one of the potential expansion trains at QCLNG.
The agreements exclude any interest in the Train 2 liquefaction facility, transmission pipeline and QCLNG project common facilities.
BG Group's Australian business QGC remains operator and retains majority ownership of the QCLNG project.