European shares finished slightly higher after a day of volatile trading.Retailers were a major drag. Swedish clothing group Hennes & Mauritz fell 3.5 percent after posting a surprise 13 percent drop in first-quarter pretax profits. That was its first quarterly profit decline in more than five years. Kingfisher, Europe’s largest home-improvement chain, also lost value as it took a big writedown for having to close over a third of stores in China. Banks were stronger and German carmaker Volkswagen surged 7.6 percent as a ten billion euro refinancing deal for parent company Porsche sparked speculation Porsche will increase its stake in VW.