That mirrored the trading pattern on Monday -- the People's Bank of China fixed the mid-point at a record high level and the yuan closed at the lower end of its daily trading band, but still up from the previous close.

The yuan traded far below the historically high mid-point fixing of 6.3198 on Thursday and edged down toward the weaker end of its daily trading limit due to bank clients' strong dollar demands.

"Spot yuan was dragged down by clients demand for US dollars," said a dealer at an European bank in Shanghai. "Now, we are waiting for the results from the meeting."

European leaders were preparing for the possibility of Greece leaving the euro zone to preserve the 12-year-old single currency at the G20 meeting on Thursday, after being shocked by Greek Prime Minister George Papandreou's call on Monday for a referendum about the rescue plan.

The growing chaos in Greece and uncertainty over the euro zone sent down stocks and commodity prices while fuelling a rush into safe-haven assets such as German bonds and the US dollar.

China's central bank set the yuan's mid-point against the dollar at record high levels this week with traders saying this was a goodwill gesture as the G20 summit convenes.

A draft G20 communique commits to move "more rapidly" toward greater exchange rate flexibility, toughening language that generally is aimed at China's rigid currency regime.

Some dealers said another reason keeping the yuan below the mid-point was arbitrage trade. The spread between the offshore market and onshore market had opened up opportunities for traders to buy dollars in the domestic market and sell them in Hong Kong.

The spread is around 456 pips between offshore yuan , at 6.3970, and spot yuan , at 6.3514. The yuan closed at 6.3573 on Wednesday.

The Chinese currency, also known as renminbi, has risen 3.75 percent so far this year and 7.48 percent since it was depegged from the dollar in June 2010.

Before trading began, the PBOC set the mid-point of the day at 6.3198, the highest level since the 2005 revaluation. The central bank uses the fixing to signal the government's intentions for the yuan.

Offshore, one-year dollar/yuan non-deliverable forwards (NDFs) ended at 6.3675, from 6.3690 at the close on Wednesday.

They implied yuan depreciation of 0.75 percent in 12 months from Thursday's PBOC mid-point, compared with depreciation of 0.62 percent they implied on Wednesday.