CBOE Holdings said its net income jumped 32 percent, even as trading in futures and options declined 16 percent in the secnd quarter.

The operator of the Chicago Board Options Exchange and other derivatives markets said net income reached $32.6 million, compared with $24.8 million in the second quarter of 2010.

Operating revenues were $120.3 million, up 7 percent from $112.6 million in 2010.

Trading volume for the second quarter was 280.2 million contracts, or 4.45 million contracts per day. Each was down 16 percent from the second quarter of 2010, when 334.4 million contracts, or 5.31 million contracts per day, were recorded.

The year-ago results included CBOE’s largest month ever for trading volume, May 2010. That included the volatility surrounding the May 6 Flash Crash of equities and derivative markets.

“Despite lower levels of trading volume industrywide in April and May, we were able to achieve solid financial results by leveraging the industry’s most diverse product line and by adhering to a strict approach to cost management,” said William J. Brodsky, CBOE Holdings Chairman and Chief Executive Officer.

Transaction fees decreased 8 percent for the quarter due to a 16 percent decline in trading volume, offset somewhat by a 10 percent increase in the average transaction fee per contract compared with the second quarter of 2010.

The average transaction fee per contract increased to $0.308 compared with $0.281 in the second quarter of 2010.