Origin went into a trading halt on Wednesday pending consideration of the revised offer. BG was originally offering a cash price of $14.70 per share, or $12.9 billion total.
Coming out of the trading halt, Origin said the revised offer of $15 plus per share, $13.6 billion total, did not take into account a CSM reserves report, which increased Origin's 3P reserves by 121%.
The report also shows a 91% increase in 2P reserves, a contingent 2C resource of 13,497 petajoules and prospective resources of 17,947 PJ.
Origin said this certified assessment confirms its position as the largest holder of CSM reserves and contingent resources in Australia, and demonstrates its record of converting resources into reserves.
Origin chairman Kevin McCann said the board had given careful consideration to all of the relevant information available, particularly the substantial increase in the company's CSM resource base and the demonstrably higher value now placed on CSM resources.
"Directors have been mindful of the certainty that a cash proposal provides for shareholders. However, based on these recent developments, the Board has decided that the revised proposal does not adequately reflect the greater value that will be
available to shareholders by not accepting this proposal," he said.
"Directors believe, having developed the largest 2P CSM reserves base in Australia, that responding to the many approaches the company has received from third parties will best accelerate the commercialisation of these resources and create increased value for shareholders."
Origin also said it took into consideration yesterday's announcement of the Santos and Petronas partnership for the Gladstone LNG project, which established a new and higher benchmark for the value of CSM.
According to Origin, the partnership demonstrates the confidence in the use of CSM for LNG production.
"It is particularly relevant to the valuation of Origin's CSM interests, which includes acreage covered by and adjacent to the acreage being acquired by Petronas," the company said.
