TMX Group Inc. posted a 61% increase in profit for the fourth quarter as the purchase of the Montreal Exchange boosted revenues, the company said Wednesday.

The operator of the Toronto Stock Exchange, Toronto Venture Exchange and Montreal Exchange said net income for the quarter ended Dec. 30, 2008 was $49 million, or 65¢ a share, compared with $30.4 million, or 46¢ a share, in the year-earlier period.

Revenue for the quarter was $151.4 million, up 36% from $111.2 million a year ago.

“The benefits of continued diversification are evident in these solid financial results. In addition to the positive contribution from trading on TSX, MX and BOX this quarter, we experienced revenue growth in both our energy segment and our market data operations while continuing to maintain cost controls and realize efficiencies,” said Michael Ptasznik, CFO, in a news release.

TMX Group said the increased revenue related to the inclusion of revenue from the Montreal Exchange and Boston Options Exchange, as well as increased issuer services, cash equity trading, energy trading and market data revenue.

The increase in revenue was somewhat offset by higher operating expenses, interest expense and a $13.3 million pre-tax mark to market adjustment on interest rate swaps, TMX Group said.

IE