Royal Dutch Shell and PetroChina have won a board recommendation from Arrow Energy after lifting their joint takeover bid for the Australian energy producer from A$4.45 to A$4.70 a share in cash.

The revised bid announced early on Monday values Arrow’s Australian assets, chiefly its reserves of coal-bed methane gas in Queensland, at A$3.5bn (￡2.1bn) and excludes the Brisbane-based group’s international operations that are worth an estimated A$400m.

Arrow is one of a number of groups aiming to invest a combined A$50bn to convert reserves of coal-bed methane into liquefied natural gas. The methane will be extracted by drilling into coal seams before it is piped overland to the coast where it will then be converted into liquefied natural gas and shipped to Asia.