Terna owns the electricity transmission grid in Italy. The company was previously a wholly-owned subsidiary of Enel, but Enel has reduced its holdings in the company in order to satisfy Italys energy liberalization goals: in 2005, Enel only held 5 percent of the shares of Terna. While Enel remains the dominant generator and distributor of electricity in Italy, other companies have emerged as significant players in the sector. The most important of these include Edison, Enipower, Acea, Energia Italia, Spains Endesa, and Belgiums Electrabel. Many of these companies have extended their market share by purchasing the former assets of Enel: subsequent to the Enel divesture in 2000 discussed above, Endesa Italia purchased Elettrogen; Edison purchased Eurogen; and a consortium of Belgiums Electrabel, Italys Acea, and Italys Energia Italia purchased Interpower, rebranding it Tirreno Power. In the summer and early fall of 2003, Italy experienced two significant power blackouts. The first occurred on June 26, 2003, when supply was unable to meet a surge in power demand as the result of increased air conditioning use during an extreme heat wave. On September 28, 2003, all of Italy, except Sardinia, experienced a second blackout, when a tree struck a power transmission pylon in Switzerland. Although it appeared that these blackouts were caused by temporary or incidental factors, many analysts have suggested that the root of the cause lies in under-investment in Italys power sector, which has resulted in less than sufficient reserve generation capacity and increased dependence on electricity imports. In response to the power crisis, the Italian government eased regulations on building new power plants and sought to encourage greater investment in the electricity sector. There have been reoccurring disputes between Italy and France concerning the liberalization of their respective electricity sectors. Italy has implemented most EU requirements relatively quickly, whereas France has been one of the slowest countries to adopt these changes. The dispute surrounding Electricite de Frances purchase of a stake in Italys Edison was only resolved after the French government agreed to allow Enel to invest in the French electricity sector. In 2006, the French government objected to Enels purchase of Frances Suez, engineering a merger between Suez and state-controlled Gaz de France to stave off the acquisition.