The European Commission gave a green light in June for the Lagardere deal on the condition that Vivendi agreed to sell its publishing group Editis, as well as its stake in Gala lifestyle magazine.

"I have no regrets," said CEO Arnaud de Puyfontaine in a call with reporters, when asked if he had regrets about the planning of the transaction. He added that the series of concessions were needed for Vivendi's next chapter.

"The rules of competition have imposed a certain number of concessions on us... we have implemented them," the CEO said.

The EU antitrust watchdog on Tuesday opened an investigation into whether Vivendi infringed merger rules during its acquisition of Lagardere with a hefty fine likely for any breach.

Vivendi has said it would cooperate with the investigation.

"We estimate that we have fully respected the applicable rules in terms of concentration, and we commit to continue to respect them until the full execution of the measures offered to the European Commission for the rapprochement with Lagardere," de Puyfontaine said.

Vivendi posted half-year adjusted revenue of 4.70 billion euros ($5.16 billion), up 3.2% year-on-year, while group earnings before interest, taxes, depreciation, and amortization (EBITDA) increased 7.7% from a year ago, to 444 million euros.

($1 = 0.9102 euros)

(Reporting by Dina Kartit, edited by David Evans and Jane Merriman)

By Dina Kartit