UPDATE 1-Renova tightens grip on Oerlikon

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ZURICH, May 9 (Reuters) - Investment group Renova increased its stake in OC Oerlikon Corp (OERL.VX: Quote, Profile, Research, Stock Buzz) to 39 percent of voting rights, tightening its grip on the Swiss engineering group, it said on Friday.

Renova, the investment vehicle of Russian billionaire Viktor Vekselberg, said the purchase of Oerlikon shares from Austrian investment group Victory would require merger clearance.

There have been long-running tensions at Oerlikon as Victory and Renova fight for control of the company, which makes everything from rocket nose cones to solar cells.

Victory, owned by Austrian investors Georg Stumpf and Ronny Pecik, will now vote together with Renova at next week's annual general meeting on the composition of the board of directors and proposed changes in Oerlikon's articles of association, Renova said.

(Reporting by Sam Cage, editing by Richard Chang)