(Reuters) - Discover Financial Services reported a 7 percent fall in quarterly profit that narrowly missed Wall Street estimates as the credit card company put aside more money to cover defaults. Discover shares fell more than 5 percent in extended trading. The payment processing network set aside $333 million to cover future bad debt, up from $136 million a year earlier. Credit card loans rose 4 percent to $50.4 billion in the quarter ended September 30. Delinquencies over 30 days fell to 1.67 percent from 1.83 percent. Net profit fell to $593 million, or $1.20 per share, in the third quarter, from $637 million, or $1.24 per share. Revenue, net of interest expense, increased 3 percent to $2.06 billion. Analysts on average had expected earnings of $1.21 per share on revenue of $2.07 billion, according to Thomson Reuters I/B/E/S. The company's shares, which have risen about 7 percent this month, fell to $51.06 in trading after the bell after closing at $53.74 on the New York Stock Exchange. (Reporting by Aman Shah in Bangalore; Editing by Don Sebastian, Maju Samuel)