The Arc De Triomphe stands while automobiles travel on the Avenue des Champs-Elysees as skyscrapers sit on the city skyline in the La Defense business district in Paris, France.LONDON — European stocks are expected to open in negative territory on Thursday as regional markets continue to see-saw this week.The U.K.'s FTSE index is expected to open 0.18% lower, Germany's DAX 0.3% lower, France's CAC 40 down 0.41% and Italy's FTSE MIB just below the flatline, according to data from IG.It's been a choppy week f ...