Europe Factors to Watch-Shares set to rally after Fed trims stimulus

PARIS, Dec 19 (Reuters) - European stocks are seen rallying on Thursday, tracking sharp gains on Wall Street after the U.S. Federal Reserve said it would trim its stimulus programme but recommitted to low interest rates. Financial spreadbetters expect Britain's FTSE 100 to open 63 to 64 points higher, or up 1 percent, Germany's DAX to open 80 to 85 points higher, or up 0.9 percent, and France's CAC 40 to open 37 to 40 points higher, or up 1 percent. Following the Fed's decision, The Dow