UPDATE 1-Mediobanca investor Bollore says happy with bank's CEO Nagel

(Adds comments from shareholder Doris)

MILAN, Oct 12 (Reuters) - Mediobanca’s second biggest investor Vincent Bollore has thrown his weight behind the Italian bank’s chief Alberto Nagel, who has come under attack by new Mediobanca shareholder Leonardo Del Vecchio.

Del Vecchio, the 84-year-old founder of eyewear giant Luxottica, has openly criticised Nagel’s management choices after snapping up 6.94% of Mediobanca last month in a surprise move that made him its third-biggest investor.

Bollore owns 7.85% of the illustrious Milanese bank which used to pull the strings of corporate Italy and still plays a prominent role in it.

The French billionaire a year ago announced he was exiting a shareholder pact that for two decades had bound his Mediobanca stake, ensuring a stable shareholder base at the merchant bank.

“Though we quit the pact after twenty years, we’ve always been, and we still are, very satisfied with the way Nagel and his team have run the bank,” a spokesman for Bollore said on Saturday.

The spokesman also denied there had been any contacts between Del Vecchio and Bollore.

Another Mediobanca investor, Ennio Doris, also praised Nagel’s work in an interview with weekly Milano Finanza on Saturday. Doris said his family could raise their stake to 1% from 0.4% at present.

“Despite going through a challenging transformation, Mediobanca never stopped paying out dividends and, virtually alone among Italian banks, never tapped shareholders for cash. All in all, it’s a really positive outcome,” Doris said.

Appointed CEO in 2008 after nearly two decades at Mediobanca, Nagel, 54, has steered the bank away from its traditional role of financial holding company, boosting its wealth management and consumer credit businesses through small acquisitions. His mandate comes up for renewal next year.

A source familiar with the situation has told Reuters Del Vecchio wants to change Mediobanca’s governance rules to give him a say in the choice of the next chief executive.

Doris said Mediobanca’s bylaws stating the CEO must be picked among executives who have been with the bank for at least three years were introduced to preserve the bank’s independence at a particular juncture and may be changed in the future.

On Friday Del Vecchio stepped up his call for changes at the bank and urged for more growth via acquisitions, after saying earlier in the week Mediobanca had to play a bigger role in investment banking in Italy and Europe. (Reporting by Valentina Za Editing by Clelia Oziel)