REUTERS/Florence Lo/File PhotoSummarySummary Companies Five big lenders post over 3.5% annual net profit growthNet interest margin shrank at all fiveNPL ratios steady or down for all fiveBEIJING, March 30 (Reuters) - China's Big Five lenders posted above 3.5% annual net profit growth this week, but warned that the foundations of the country's recovery were "not yet solid". China's Bank of Communications Co Ltd (BoCom) (601328.SS), and Bank of China (BoC) (601988.SS) both posted just over 5% annual net profit growth on Thursday. Even higher figures came from the Agricultural Bank of China Ltd (601288.SS) (AgBank) on Thursday and China Construction Bank Corp on Wednesday, which both posted over 7% annual net profit growth. Industrial and Commercial Bank of China (ICBC) (601398.SS), , the world's largest listed lender by assets, came in at 3.5% annual net profit growth. NPLsWhile all five lenders posted steady or falling non-performing loan ratios, they also logged shrinking net interest margins (NIM), a key gauge of bank profitability.

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