BEIJING -- China's foreign exchange watchdog said Wednesday that Chinese banks' foreign exchange surplus from bank-to-client transactions reached $43.2 billion in July.

In July, institutional and individual clients sold $136.1 billion in foreign exchange to banks while purchasing $92.9 billion, the State Administration of Foreign Exchange (SAFE) said in an online statement.

From January to July, more foreign currencies were sold than purchased through Chinese banks, resulting in $316.9 billion of foreign exchange surplus during the period, the statement said.

Foreign exchange surpluses, which make up part of the country's foreign exchange reserves along with current account surpluses and foreign direct investment inflow, do not include banks' own foreign exchange transactions or interbank transactions, according to SAFE.

Last year, foreign exchange surpluses created through Chinese banks' transactions with domestic clients increased 51 percent year-on-year to reach $397.7 billion, SAFE data showed.