The value of both Activision and Vivendi's stock increased during the first day of trading following the announcement of a merger between the two companies.
On a day when the US stock markets declined, Activision shares were up USD 2.82, or 12.73 per cent, to close at US 24.97.
In Paris, Vivendi's shares rose just slightly, up 1.02 per cent to 31.71 Euro.
Meanwhile, shares of The9 Ltd., the Chinese company which operates Vivend's World of Warcraft in China, declined 9.39 per cent to USD 23.35.
EA owns a 15 per cent stake in The9, and some analysts expressed concerns that the Activision/Vivendi merger could affect future publishing decisions.
The9's World of Warcraft publishing contract expires in 2009. Currently, more 80 per cent of the company's revenue comes from publishing the game according to a Goldman Sachs analyst.