Shares of Activision Blizzard Inc. soared in Friday morning trading on the news that it will buy back a significant stake in the company from Vivendi SA.

The Santa Monica video game publisher announced late Thursday night that it will buy 429 million of Vivendi’s shares for $5.8 billion, or $13.60 a share. A group of investors, led by Activision Chief Executive Bobby Kotick, will also purchase 172 million shares from Vivendi for more than $2.3 billion.

Activision shares on Friday closed up $2.28, or 15 percent, to $17.46 on the Nasdaq.

Mike Hickey, an analyst at Benchmark Company in Denver, said the deal could give Kotick and his executive team more flexibility to help Activision evolve with the changing video game landscape.

“For Bobby and his team to get control back and move forward in the direction that they want is a huge positive,” he said. “It didn’t feel like his endgame was to sell to Vivendi. If you think back to how he’s built this company, you can tell that he still has a passion to grow.”

When the acquisition is completed in September, Vivendi will retain a minority stake of about 12 percent in the company. Kotick’s investment group, ASAC II LP, will own 25 percent.

Activision will fund the acquisition with $1.2 billion in cash and $4.6 billion in debt financing.

Vivendi merged its $8.1 billion Blizzard Entertainment division with Activision in 2008 to create Activision Blizzard Inc. The French conglomerate paid $1.7 billion in cash to obtain minority control of the reorganized company.

But Vivendi has been looking to offload some of its stake in Activision in an attempt to reinvigorate the business and focus on its music and film divisions.

Activision conducted a conference call with investors Friday morning where it previewed adjusted second quarter earnings of 8 cents per share, ahead of analysts’ projections, on revenue of $608 million. The company will report full earnings on Aug. 1.