Royal Dutch Shell is in no hurry to sign off on its Bowen Basin liquefied natural gas joint venture that’s projected to cost $20 billion as it focuses on cheaper East African projects.

‘‘We see a cost advantage in East Africa over Australia at the moment,’’ Andy Brown, Shell’s director of international production, said in an interview in London. ‘‘We aren’t going to rush into the final investment decision.’’

Shell and PetroChina are drilling in Queensland to prove gas resources for their proposed Arrow LNG plant, which would have a capacity of about 9 million tonnes a year and may cost more than $20 billion, according to Deutsche Bank. At the same time, Shell is drilling in Tanzania and this year was outbid for Cove Energy Plc as it sought assets in Mozambique.

Mozambique may hold as much as 250 trillion cubic feet of gas, national oil company Empresa Nacional de Hidrocarbonetos estimated this month after explorers made the decade’s biggest discoveries in its waters. Shell may scale back LNG export projects in Australia and switch to East Africa where the new prospects will cost about half as much to develop, according to Jefferies International.

‘‘East Africa will be a major source of LNG,’’ Brown said. ‘‘It really is in virgin territory and that would require an enormous amount of activity to build sensitively and sustainably a mega LNG facility.’’

Mozambique GasGlobal oil companies are expanding in LNG as Asian demand for the liquefied fuel drives prices higher. The Hague-based Shell and France’s Total SA have been in talks with Anadarko Petroleum Corp. and Eni SpA about buying into gas fields off Mozambique with enough fuel to meet Asia’s needs for at least five years.

‘‘We continue to be interested in Mozambique,’’ Brown said. ‘‘We will have a legitimate role.’’

While companies jostle for resources off Africa, competition to secure Australia’s gas for export has also intensified. Shell alone plans to invest $30 billion in the country over the next five years.

Shell and PetroChina’s Arrow Energy will compete with at least three other projects under construction in Queensland: the Santos-led Gladstone LNG; BG Group’s Queensland Curtis LNG; and ConocoPhillips’s Australia Pacific LNG.

Shell has been a partner in six other LNG ventures in Australia and yesterday cut the first steel for its Prelude floating LNG unit off the northwest coast, which will be the biggest such vessel in the world when completed.

Bloomberg