Shanghai-based online game operator The9 Limited has announced that it will be expanding its exclusive World of Warcraft license agreement with Blizzard Entertainment to roll out Wrath of the Lich King in mainland China.

This agreement follows The9's announcement last week that World of Warcraft reached a record peak concurrency of 1 million in China, the highest concurrency since the subscription-based MMORPG's launch in June 2005.

In the past, The9 has managed the operation and distribution in the Chinese market for World of Warcraft's first expansion pack, The Burning Crusade, as well as for other MMORPG titles, like Hellgate: London and Ragnarok Online 2.

Blizzard and The9's deal to publish The Burning Crusade last year came only after months of speculation and stalled negotiations, with Blizzard at one point announcing its intentions to explore alternative partnerships for its World of Warcraft operations in China.

The two companies announced their deal shortly after The9's Hannah Lee resigned from her position as senior vice president and CFO.