Professional video game league Major League Gaming has raised another $7.5 million, an addition to its second venture round from 2006. The new financing will presumably help the New York company weather the economic downturn, although it’s reporting impressive growth for 2008.

Major League Gaming says it’s the largest organized video game league around and also the largest international “sanctioning body.” (Other leagues include the Global Gaming League and World Cyber Games.)  Players can compete against each other on the company’s sites as well as at in-person competitions.

The company’s sites hosted 4.4 million online matches in 2008 and received 7 million unique visitors each month, up 625 percent and 109 percent, respectively, from 2007. On average, 15,000 people attended each of the live competitions, and there’s a growing audience that wants to watch, even if it hasn’t exactly reached NFL or NBA levels. October’s Dallas Playoffs were the year’s high point, with 503,000 men under 30 watching online. (The company didn’t provide numbers about women, or about men over 30.)

Founded in 2002, Major League Gaming previously raised $35 million. Oak Investment Partners, which led the startup’s $25 million second round, also provided this follow-on investment.