Spanish telecom giant Telefonica said Wednesday it had sold its 8.2 percent stake in Telecom Italia to French media group Vivendi, in a deal estimated to be worth more than 1 billion euros. In return, Vivendi transferred a 4.5 percent stake that the French company had earlier acquired in Telefonica's Brazilian subsidiary back to Telefonica. The deal was one of a series of transactions in a complex agreement signed on Sept. 19 for Telefonica to take control of Brazilian telecom firm GVT from Vivendi. Telefonica said the deal would yield it a pre-tax gain of 380 million euros. The deal also boosted Vivendi's stake in Italy's biggest telecom provider to 14.9 percent, Bloomberg reported. It said Telefonica sold the shares for about 1.03 billion euros.