Blizzard Entertainment, publisher of the best-selling MMO World of Warcraft, said on February 29th that it is going to be cutting its staff by 600 employees.

“Constant evaluation of teams and processes is necessary for the long-term health of any business,” Blizzard president Mike Morhaime said. “Over the last several years, we’ve grown our organization tremendously and made large investments in our infrastructure in order to better serve our global community. However, as Blizzard and the industry have evolved we’ve also had to make some difficult decisions in order to address the changing needs of our company.”

These layoffs are the biggest in the company’s history.   The Irvine, California based company currently employees 5,000 employees so 600 people is a large percentage of the company.

The cuts are speculated to focus on the company’s community service department, especially the World of Warcraft customer service department. World of Warcraft, the company’s flagship title, has seen its subscriber numbers fall from 12 million in 2010 to 10.2 million subscribers in the last quarter.

Atul Bagga, an analyst at Lazard Capital Markets, said that the layoffs were probably 20 to 30 percent of the company’s customer service staff. He said the reduction is likely linked to the downward slope of World of Warcraft usage. He believes that WoW’s subscriber base will fall to as low as 300,000 users in the current quarter, due to competition from titles such as Star Wars: The Old Republic and a lack of new content for WoW.

Blizzard said that these cuts will not affect the games currently in development and says it remains committed to shipping several games this year, including Diablo 3, Blizzard DOTA, and expansions for Starcraft 2 and World of Warcraft. Blizzard will reportedly announce Diablo 3’s release date in the coming weeks.