Enel Moves to Increase Stake in Endesa

Italian energy company Enel said Friday it has entered into a share-swap transaction with Italian bank Mediobanca Banca di Credito Finanziario for an additional 4.5 million shares in Spanish power company Endesa that could raise its hold in the utility to 22%.

The new shares account for a 0.43% stake in Endesa. Enel previously had disclosed share swaps accounting for an 11.58% stake in the company, on top of the 9.99% stake it already acquired in the open market earlier this week.

The share-swaps operations, or derivatives, need to be approved by Spain's energy regulator.

Enel's moves to snap up stock in Spain's No. 1 power utility has threatened German's E.On AG's 17-month struggle to buy Endesa, a 41 billion euros ($54.24 billion) bid that has been opposed by Endesa's biggest shareholder, Acciona, which has 21%.

E.On's bid faces a crucial hurdle March 20 when Endesa shareholders are to vote on E.On's request that Endesa remove a 10% cap on voting rights for each shareholder, no matter how great the stake. It is a key condition of the offer.

Potentially, Acciona and Enel could band together to help block the change if enough shareholders are absent or share the view.

E.On has confirmed that it cannot raise its current 41 billion euros offer for Endesa during the current public offering period, which extends until March 31. It is bound by Spanish market regulator and SEC prohibitions from doing so.

If E.On is successful, the deal would result in the largest ever cross-border utility takeover in the continent's history. The tie-up would create a global energy giant with more than 100,000 employees, 50 million customers in Europe, the U.S. and Latin America.

Endesa's shares were down 0.6% at 38.55 euros. E.On fell more than half a percent to 97.05 euros ($128.35) in Frankfurt trading.