Operating revenues for the second quarter of 2012 rose 10% to $132.54m, compared to $120.29m for the same period a year ago.

The increase in operating revenues was primarily driven by increases of $8.6m in transaction fees, $1.5m in market data fees and $3.6m in exchange services and other fees, offset somewhat by a decrease of $0.9m in access fees.

Operating income was $66.06m for the quarter, compared to $56.45m for the same period in the previous year.

Transaction fees increased 10% for the quarter due to an 8% increase in trading volume and a 2% increase in the average transaction fee per contract compared with last year’s quarter.

CBOE Holdings executive vice president and CFO Alan Dean said, "Along with growing operating revenues by 10 percent, our disciplined expense management yielded an increase in operating income of 17 percent, which generated an operating margin of 49.8 percent, a gain of 290 basis points compared with second quarter 2011."