(Adds financial details, background on NEX acquisition)
NEW YORK, July 31 (Reuters) - CME Group, one of the world's largest exchange operators, on Wednesday reported a drop in second-quarter earnings, partly due to higher expenses as it integrates the recent $5 billion acquisition of trading platform operator NEX.
Net income fell to $513.8 million, or $1.43 per diluted share, in the quarter ended June 30, from $566.1 million, or $1.66 per diluted share, a year earlier.
CME, which owns the Chicago Board of Trade and Chicago Mercantile Exchange, closed the acquisition of NEX in November, adding bonds, swaps and spot currencies to its futures complex, and has been working to integrate the businesses and expand product offerings.
Excluding one-time costs, including merger and acquisition expenses, the company earned $1.76 per share, meeting the mean estimate of analysts, according to IBES data from Refinitiv.
The Chicago-based company said average daily volume rose 14% to 20.9 million contracts, compared with a year earlier.
Clearing and transaction fees revenue rose 16% to $1.1 billion from a year earlier, while the total average rate per contract dropped 8.4%t to $0.693, partly due to higher discounts.
Expenses were up 46.1% to $574.1 million.
Total revenue at CME rose 20.1% in the quarter to $1.27 billion. (Reporting by John McCrank Editing by Susan Thomas)