Royal Dutch Shell announced it cleared a regulatory hurdle for the planned combination with BG Group from an Australian financial regulator.

The Australian Foreign Investment Review Board approved the planned merger of the two energy giants, Shell said. The FIRB helps the government's policies on foreign investments.

The FIRB comes three weeks after the proposed merger cleared the Australian Competition and Consumer Commission, a move Shell Chief Executive Officer Ben van Buerden said was a "a sign of Shell's confidence in the Australian economy."

The FIRB's nod came with a condition related to taxation arrangements and calls on the Dutch supermajor to undertake a "cooperated compliance approach" to the Australian tax regime, the Sydney Morning Herald reported.

Speaking Tuesday, Australian Treasurer Scott Morrison said the government welcomes foreign investments provided it aligns with the national interest.

"Without foreign investment, production, employment and income would all be lower," he said. "But it is important that foreign investment is appropriately monitored to ensure that it benefits all Australians."

BG Group is one of Australia's largest natural gas producers. Last month, it started commercial operations at the second train, a liquefaction and purification facility, at its Queensland Curtis plant in Australia. The company's Australian subsidiary also took control of the train from Bechtel Australia, which built the facility.

The $70 billion merger with Shell would be the one of the largest acquisitions since the Exxon Mobil merger was completed in 1999. The combination still needs the consent from the Chinese Ministry of Commerce.

The companies say they expect the merger will be completed in early 2016.