UPDATE 1-EDF sees 2018 rebound but nuclear output lower again in 2019

UPDATE 1-EDF sees 2018 rebound but nuclear output lower again in 2019: * Long French nuclear outages weigh on core earnings* 2018 rebound seen but 2019 nuclear output seen lower again* One million customers lost in 2018 to sharp competition* EDF shares climb more than 5 percent(Adds quotes, detail, market opening)By Geert De ClercqPARIS, Feb 16 (Reuters) - EDF's 2017 core earningsfell 16.3 percent as the French utility struggled with nuclearreactor outages and lost a million customers, but its chiefexecutive said he expected a rebound this year.Last year, EDF suffered extended unplanned outages as wellas longer-than-expected maintenance outages at several of its 58nuclear reactors in France, while the nuclear regulator orderedits four reactors in Tricastin, southern France, shut down formonths for safety reasons.The outages led to a 21 percent drop in French electricitygeneration income to 4.8 billion euros, as nuclear powergeneration fell to 379 terawatthours (TWh), well below itsinitial target of 390-400 TWh. When all its reactors are up anrunning, EDF can produce up to 420 TWH per year.For this year, EDF forecasts output of at least 395 TWH.EDF chief executive Jean-Bernard Levy said market conditionshad been difficult in nearly all the firm's busin