European Factors to Watch-Shares seen lower with all eyes on Greece
LONDON, June 26 (Reuters) - European stocks were seen opening slightly lower on Friday, with investors discouraged by a lack of progress in Greek debt crisis talks but wary of making firm bets in either direction ahead of a critical weekend of negotiation. Greece failed again to clinch a deal with its international creditors on Thursday, setting up a last-ditch effort on Saturday to avert a default next week or start preparing to protect the euro zone from financial market turmoil. Fin