China will continue to buoy the global economy even if the Asian giant's growth stabilizes at current levels of 7-8 percent a year, Australian Treasurer Wayne Swan said on Sunday.

Swan, in Mexico to attend meetings of Group of 20 finance ministers and central bankers, said a lack of growth was weighing on the global outlook and urged policymakers to act swiftly to fix problems.

But he said China's slowdown from breakneck growth rates of more than 14 percent in mid-2007 to an expected 7.5 percent this year had been misrepresented.

"Much of the discussion about the growth rate in China doesn't appreciate the fact that the Chinese economy is now 40 percent larger than it was at the end of 2007," Swan said in an interview before the meeting.

"If it's 40 percent larger and the growth rate is 7 or 8 (percent), they are still making a very significant contribution to global growth."

Australia is heavily dependent on China as a buyer for its commodity exports and recent upbeat data has fanned hopes that China's economy may be picking up.

Annual growth is expected to accelerate to 7.6 percent in the next quarter from 7.4 percent in the third quarter, snapping a seventh straight quarter of slower expansion and paving the way to beat the full-year target of 7.5 percent.

Still, G20 countries named a weaker pace of expansion in some emerging markets as a risk to the global outlook, along with Europe's ongoing debt problems and looming fiscal tightening in the United States and Japan.

Swan said both Europe and the United States had to act swiftly to resolve their challenges in the interests of lifting global growth out of the doldrums.

"Even in Australia and Asia more broadly the lack of growth coming out of Europe on the one hand and out of the United States on the other is now beginning to weigh very heavily," he said, adding that U.S. policymakers needed to move quickly to avoid a year-end combination of spending cuts and tax hikes.

"They need to act swiftly on the fiscal cliff and then they will need to put in place a medium-term fiscal consolidation that recognizes that in the shorter term there may well need to be a boost to growth consistent with a medium-term and long-term fiscal consolidation," Swan said.

(Reporting by Krista Hughes; Editing by Kieran Murray and Chizu Nomiyama)