BG Group has said its takeover by Shell has been given the green light by the Chinese regulatory authorities.
China's approval was the last piece in the regulatory puzzle for Shell, which must now be cleared by shareholders. The takeover is on track for completion by early next year.
The combined companies will be the largest natural gas trader in the world and rival Exxon Mobil as the world's biggest natural oil company.
The deal was reported to be worth $70 billion when it was first announced. It has already been approved by Australia, Brazil and the EU.
Some analysts have questioned the wisdom of the deal as the oil price has continued to slide. Oil was $55 a barrel on April 8 when the merger was first announced but has plummet to below $40 a barrel since.
Standard Life's David Cumming told the BBC that the oil price would need to be between $60 and $70 for the maths to work.
He said the three options now are for Shell to walk away, seek to change the terms of the deal, or for shareholders vote it down.
Helge Lund, BG Group's chief executive, said in statement announcing China's approval that the deal still made sense. "The proposed combination has strong industrial logic, particularly in deep water production... and will accelerate the delivery of value to our shareholders," he said.
