* Genish named Telecom Italia general manager for operations
* Further announcements on governance in September
* Combination of TIM with Mediaset not on agenda
* Idea of separating fixed-line network to be discussed in future (Adds Genish's appointment)
MILAN, July 28 (Reuters) - Telecom Italia named Vivendi's Amos Genish as its general manager for operations on Friday as the French media giant tightened its grip on the Italian phone group, where it is the largest shareholder.
The appointment comes after Telecom Italia (TIM) parted ways with Chief Executive Flavio Cattaneo, who is leaving the company after only 16 months in the job following clashes with Vivendi , which holds a 24 percent stake.
Genish, whose latest job was chief convergence officer at Vivendi, formerly headed the Brazilian subsidiary of Spanish operator Telefonica and founded GVT, a Brazilian mobile operator.
A 57-year-old former Israeli army captain, he will oversee al of TIM's operations and be based in Rome, the company said in a statement, confirming a Reuters report.
Cattaneo is the second CEO to leave TIM in less than two years after locking horns with the French group led by billionaire Vincent Bollore, whose stated ambition is to build a southern European media powerhouse.
TIM's executive chairman Arnaud de Puyfontaine, who also serves as Vivendi CEO, is taking on most of Cattaneo's powers on a temporary basis.
In a conference call with analysts following first-half results, the Frenchman said further announcements on governance will be made in September.
Some investment funds that hold TIM's shares have taken the latest leadership change in their stride, betting on Genish to complete the company's overhaul with a burst of deals - from a possible sale of the Brazilian unit to a spin-off of the Italian fixed-line network.
Questions about potential M&A moves dominated the analyst call, but de Puyfontaine said he rejected speculation that has appeared in the press, declining further comment. The stock retreated after his comments and traded down 1 percent.
De Puyfontaine said a combination of TIM with Mediaset , in which Vivendi has built up a stake of 29 percent angering the Berlusconi family who is the broadcaster's top shareholder, was "not on the agenda".
He said a plan to set up a joint venture between TIM and Vivendi's pay-TV unit Canal+, which would foster Vivendi's goal of expanding content distribution across platforms, would be examined next month. A source close to the matter said first production could start in October.
Regarding TIM's Brazilian unit, the company's only asset abroad, he said "Brazil is part of the group and the good job that has been done by the team is going to be pursued", without elaborating.
The idea of TIM exiting Brazil has been gaining traction among investors since Vivendi became a top shareholder, because the French group sold its own Brazilian operations before investing in Italy.
Genish's arrival only reinforces that expectation: he sold GVT to Vivendi in 2009 and five years later convinced Vivendi to sell it on to Telefonica, making a capital gain of $4 billion for the French.
Asked about the future of TIM's fixed-line network, estimated by analysts to be worth up to 15 billion euros, de Puyfontaine said he would keep an "open mind."
He said the idea of separating the network - an option favoured by the Italian government - was "interesting" and "something that will be discussed in future", but it was not part of the company's current business plan.
Rome, where Vivendi's growing influence on Italian business is under scrutiny, considers the network as strategic and some ruling-party lawmakers say it should be state-controlled, a neutral platform open to all. (Additional reporting by Mathieu Rosemain in Paris; Editing by Keith Weir)