In the 47-page document, Santos chairman Stephen Gerlach described the $606 million, or $1.26 per share, unsolicited offer for the coal seam methane producer as “compelling”.

“Santos believes the offer is compelling for QGC shareholders, offering the certainty of cash consideration at a significant premium to recent QGC share prices and other relevant benchmarks,” Gerlach said.

The offer represents an attractive reserves valuation multiple of $1.38 per gigajoule of proved and probable gas reserves, compared with an average of 57c/GJ for other comparable transactions, he said.

Gerlach also reiterated that the offer represented a 24% premium to QGC’s closing share price of $1.02 on October 3, the day before it announced its intentions.

However, QGC’s share price has soared and remains well above the offer price since news of the takeover bid emerged.

Yesterday, QGC closed on the Australian Stock Exchange at $1.47 and opened this morning slightly lower at $1.465.

In an earlier announcement, QGC founder and chairman Bob Bryan described the share price rise as a sign the market backed his board’s view that the company would continue to grow.

“Given the quality of QGC’s coal seam gas prospects and the top performance of its management, the board has every reason to believe that the value of QGC will continue to increase,” he said.

“Since the Santos bid was announced, not a single share has been traded at the offer price of $1.26,” he said.

QGC’s board has unanimously rejected the offer and its directors have “strongly advised” shareholders not to take any action.

Due to close on November 30, the offer is subject to certain terms being met, including a 50.1% minimum acceptance condition.