The amount of deposits held at China's Big Four banks increased in June after showing a tendency to fluctuate during the past few months.

Central bank data showed that deposits held at Commercial Bank of China, Agricultural Bank of China, Bank of China and China Construction Bank increased by a total of 1.8 trillion yuan ($282.5 billion).

The increase is widely seen as being the result of lenders' efforts to ensure they have a loan-to-deposit ratio of 75 percent. Regulators and lenders' internal control departments typically check the ratio at ends of quarters.

Last month, the central bank allowed lenders to set their deposit rates up to 1.1 percent higher than the benchmark, prompting commercial banks to begin competing more fiercely to attract depositors.