The Chinese yuan dollar rate fell to as low as 6.84 on Monday after the central bank set the midpoint at a seven year low, following the dollar's best week in a year.

The People's Bank of China set the midpoint rate at 6.8291 per dollar. That was about 0.26 percent weaker than the previous fix. The onshore yuan against the US dollar dropped 254 pips on Monday against the previous close.

The central bank is widely believed to have sold U.S. dollars to cushion the descent of the yuan. Data on Monday shows the PBOC sold a net 39.2 billion US dollars worth of foreign exchange in October, easing from an eight-month high in September.