LONDON, Dec 4 (Reuters) - European stocks are seen edging lower at the open on Tuesday as U.S. budget negotiations to delay growth-curbing austerity measures hit a roadblock and key regional indexes hit resistance levels. Financial spreadbetters expected Britain's FTSE 100 to open 14 to 17 points lower, or as much as 0.3 percent, Germany's DAX to open 23 to 26 points lower, or as much as 0.3 percent, and France's CAC 40 to open 7 to 9 points lower, or as much as 0.3 percent. The Whit