Royal Dutch Shell's planned mega-takeover of British rival BG Group cleared another hurdle Thursday as Australia's competition commission said it would not oppose the move amid gas market concerns.

It means Shell's £55-billion (US$84-billion, 79 billion-euros) takeover of BG remains on track for completion in early 2016.

"BG Group plc today confirms that the recommended cash and share offer for the company to be made by Royal Dutch Shell has received unconditional merger clearance from the Australian Competition and Consumer Commission," a BG statement said.

Separately, ACCC chairman Rod Sims said the "proposed acquisition would be unlikely to substantially lessen competition in the wholesale natural gas market, in either Queensland or eastern Australia more broadly".

BG Group noted that the approval was one of the five regulatory clearances required. The European Commission and Brazil's competition authority have already cleared the way for the tie-up, leaving only Australia's Foreign Investment Review Board and China's Ministry of Commerce to follow suit.

The proposed transaction requires also support from shareholders of both companies.

The BG deal is aimed at helping Shell boost its flagging output thanks to BG's strong position in liquefied natural gas (LNG), a cleaner alternative to coal and nuclear energy.