French media and telecommunications conglomerate Vivendi SA has hired two investment banks to explore a sale of its majority stake in Santa Monica video game publisher Activision Blizzard Inc.

The Wall Street Journal reported Tuesday that the banks, Goldman Sachs Group Inc. and Barclays PLC, have approached prospective buyers that include video game makers and private equity firms.

Vivendi was rumored to be trying to sell Activision Blizzard for weeks. The news was confirmed for the first time last week by the company’s Chairman, Jean-Rene Fourtou, at the Allen & Co. media conference in Sun Valley, Idaho. Vivendi is working to reduce its debt load and boost its share price, which hit a nine-year low earlier this year.

Activision is the company behind blockbuster video game franchises “Call of Duty” and “World of War Craft.” But as the console business on which “Duty” is played faces pressure from mobile gaming and cloud-based alternatives, analysts have noted that it has been hard to find a buyer for the 61 percent stake, which is valued at about $8.2 billion.

Another possibility is for Activision to buy the position, which originated when Activision merged with Vivendi’s gaming division five years ago. Such an option would likely require Activision to borrow money because it has about $3 billion in cash.

Shares of the video game publisher fell slightly Tuesday to $12.08.