experienced a third straight month of deficit in foreign exchange transactions as the country's growing appetite for foreign currency expands, according to new data published Tuesday.

Chinese banks' forex purchases registered at 841.4 billion yuan (136.9 billion U.S. dollars), while sales stood at 1.01 trillion yuan in October, according to data from the State Administration of Foreign Exchange (SAFE).

As a result, the banks saw a transaction deficit of 167.3 billion yuan, up from 100.6 billion yuan in September and 5.1 billion yuan in August, when Chinese banks posted their first monthly net forex purchase in 13 months.

In the first 10 months, Chinese banks bought 9.61 trillion yuan worth of foreign currency and sold 8.72 trillion yuan, resulting in net forex purchase of 886.7 billion yuan.

The fluctuation in foreign exchange transactions is the main contributor to changes in China's foreign exchange reserves.