Chinese banks purchased foreign exchanges (forex) worth $164.7 billion in November while selling $128.1 billion, for a surplus of $36.6 billion.

It marked the fourth month of surplus since August, after a deficit in June and July, according to the State Administration of Foreign Exchange.

Analysts attributed the surplus to the growth of the economy, appreciation of the yuan and delay of the U.S. Federal Reserve's gradual tapering of quantitative easing.

Foreign exchange transactions are a major cause of fluctuation in China's foreign exchange reserves, and the November surplus indicates a slowing outflow of foreign capital.

In the January-November period, forex purchases stood at $1.7 trillion and sales, $1.46 trillion, with a surplus of $239.2 billion.