China Construction Bank (CCB) said Friday in a quarterly report that its non-performing loan ratio had dropped to 8.88 percent by the end of March, the lowest among China's "Big Four" state-owned banks.

Operating profits shot up 32.4 percent year-on-year to 15.97 billion yuan (1.9 billion US dollars) in the first quarter of the year, the bank said.

CCB used part of its profits to set provisions for and dispose of the existing problem assets, which analysts acknowledge were piled up due to excess lending to money-losing state-owned enterprises over the past decades.

In the first three months, the bank either recovered or wrote off 2.5 billion yuan (301.2 million dollars) in non-performing loans in compliance with the internationally accepted five-category classification system.

The Construction Bank, paired with the Bank of China, is conducting joint-stock reform on a pilot basis prior to public listings, but hindered by the bad assets problem.

China's State Council injected 45 billion US dollars in foreign exchange reserve into the two banks to replenish their capital in cash.

According to the latest report, CCB's own assets added 154.7 billion yuan (18.6 billion dollars) from January to March, bringing the outstanding amount to 3.68 trillion yuan (443.4 billion dollars) by last month-end.