The record trading volume seen in the third quarter was a boon for exchange operators who had been seeing declining revenue for the first part of the year.

Exchange operators such as Deutsche Borse, Nasdaq OMX and the Singapore Exchange were among the first to post their financial results from the preceding three months, with each seeing substantial boosts to their earnings.

Frankfurt’s Deutsche Borse during the third quarter experienced its best three-month financial performance in more than three years. According to its preliminary numbers, the company had Ebit of $500 million on revenue of $848.9 million, increases of 46 percent and 20 percent respectively, year-over-year.

“Our results for the third quarter show very strong performance of our business,” said Gregor Pottmeyer, chief financial officer of Deutsche Borse in a statement. “At the same time we have further accelerated our efficiency measures and have cut our guidance for total costs in 2011. We are very confident on our future earnings power and have therefore decided to implement a share buyback program.”

The share buyback program lasts up until the earlier of the completion of the Deutsche Borse and NYSE Euronext merger or Dec. 31. The overall purchase volume will amount to around $140 million.

Starting Thursday, a two-day hearing is scheduled before regulators in Brussels where executives from Deutsche Borse and NYSE Euronext will have the opportunity to defend the merits of their proposed deal. A final decision on the merger is expected from regulatory authorities by Dec. 22.

Nasdaq OMX earlier in the week announced earnings of $110 million, compared with $101 million from the same time last year and $92 million from the second quarter of 2011. Revenue increased to $438 million from $372 million last year.

The SGX last week announced $88 million in profit on $159 million in revenue for the three months ended Sept. 30.