World of Warcraft lost 1.3 million subscribers over the first three months of 2013, Blizzard has revealed in a quarterly report.

However, it still has eight million subscribers and remains “the number one subscription-based MMORPG in the world,” said Activision CEO Bobby Kotick.

"While we do believe further declines are likely, and we expect to have fewer subscribers a year than we do today, World of Warcraft remains one of the most successful franchises in the history of entertainment," he said.

Blizzard plans to release more content more frequently to keep current players engaged, he added.

"We believe in the long-term value of this franchise and will continue to commit substantial resources to World of Warcraft.”

In related news, EA Labels president Frank Gibeau has told investors that monthly revenue from Star Wars: The Old Republic has more than doubled since the switch to free-to-play was made last November.

According to Gibeau, 1.7 million new players have signed up for free-to-play accounts since then, and paid subscription numbers have stabilised at just under half a million.

“And as we look forward, we're going to continually invest in new content for the service and for players every six weeks or so," he said.