French media conglomerate Vivendi has come under enough financial pressure that may force it to offload one of its crown jewels: Activision Blizzard.Vivendi is strangled by a pile of only slowly declining debt that currently stands at about $15.5 billion. The sale of Activision Blizzard, which is majority-owned by Vivendi, could alleviate the growing pain substantially. The 60 percent stake Vivendi holds is estimated to be worth about $10 billion. According to Reuters, Vivendi may have started fielding potential buyers, which reportedly include Time Warner as well as Microsoft.When asked for comment, both companies declined to comment on Activision Blizzard, but did not deny their interest either. Similarly, Vivendi did not deny that Activision Blizzard is for sale and said that "all options are on the table". As attractive as Activision Blizzard may be as a game publisher, it would be relatively easy for Vivendi to part ways as it is not a core business for the company.Founded back in 1853, and headquartered in Paris, Vivendi's heart is in music publishing and TV broadcasting.