TORONTO, Aug 25 (Reuters) - National Bank of Canada (NA.TO) beat analysts" estimates for quarterly profit on Wednesday, as the bank reversed earlier provisions for credit losses and saw strong performance across business segments compared with a year earlier. Net income excluding one-off items rose to C$839 million ($665.7 million), or C$2.36 per share, in the three months ended July 31, compared with C$602 million, or C$1.66 per share, a year earlier. Analysts were expecting income of C$2.13 a share, according to IBES data from Refinitiv. Adjusted income before provisions for credit losses and income taxes at Canada"s sixth-largest lender rose to C$1.09 billion from C$947 million a year earlier. ($1 = 1.2598 Canadian dollars)