Chinese online gaming firm Changyou.com Limited today announced its unaudited financial results for the first quarter ended March 31, 2010.

Total revenues reached USD72.1 million, an increase of 2% quarter-over-quarter and 17% year-over-year. Net income hit USD39.7 million, and aggregate registered accounts for the company’s games grew 8% quarter-over-quarter and 38% year-over-year to 87.4 million.

Both gross margin and non-GAAP gross margin in the first quarter of 2010 were 93%, which was roughly in-line with 92% in the fourth quarter of 2009 and 94% in the first quarter of 2009. For the first quarter of 2010, total operating expenses were USD21.4 million, up 2% quarter-over-quarter and 6% year-over-year. Non-GAAP operating expenses were USD18.5 million, up 4% quarter-over-quarter and down 5% year-over-year.

Operating profit for the first quarter of 2010 increased 2% quarter-over-quarter and 19% year-over-year to USD45.3 million.

As of March 31, 2010, Changyou had a net cash balance of USD265.4 million, up from USD226.9 million as of December 31, 2009. Operating cash flow for the first quarter of 2010 was a net inflow of USD43.3 million.