Covington & Burling and Slaughter and May have advised China's biggest gaming group Tencent on the purchase a majority stake in 'Clash of Clans' mobile game maker Supercell from Japan’s SoftBank in a deal valued at $8.6 billion.

Tencent will acquire about 84.3 percent of Supercell via a wholly-owned consortium, including all of SoftBank's 72.2 percent stake,  according to Reuters. The sale is one of the world's biggest-ever gaming deals.

Fenwick & West and White & Case acted as legal advisors to Finnish gaming company Supercell. SoftBank was represented by a Morrison & Foerster team led by partner Kenneth Siegel, along with partners Eric McCrath, Lauren Bellerjeau, Ivan Smallwood, Tom McQuail and Jeff Jaeckel, as well as law firm Hannes Snellman represented SoftBank.

Clash of Clans is a war strategy game in which players build fortresses, form clans and battle it out with other clans in a Medieval-style fantasy world. Supercell has a handful of other successful games, including  'Boom Beach' and 'Hay Day,’ and gets revenue from in-game purchases.