China's central bank stepped up its gold purchases as prices fell in September, recording the biggest monthly increase in its official gold reserves in three years, official data showed on Wednesday.

The country's gold reserves rose by 740,000 ounces to 77.47 million ounces as of the end of September, marking the 23rd consecutive month of purchases, according to the People's Bank of China.

The latest increase was the largest since September 2023, when reserves rose by 840,000 ounces, according to market tracker Wind Info. It also exceeded the increases of 650,000 ounces in August and 640,000 ounces in July.

Meanwhile, China's foreign exchange reserves stood at $3.4 trillion at the end of September, down $38.1 billion, or 1.11 percent, from a month earlier, the State Administration of Foreign Exchange said.

SAFE attributed the decline to the combined effects of currency translation and changes in asset prices, as the US dollar index rose and prices of major global financial assets generally fell during the month.

China's economy remained broadly stable, with new growth drivers gaining strength, supporting the overall stability of foreign exchange reserves, SAFE said.