Nikkei rises to fresh 15-year high on ECB; FamilyMart falls on merger talks

* FamilyMart falls, UNY rises on merger talk news * Nikkei may reach 19,400 at the end of the month - analyst * Nikkei heads for 4 straight week of gains By Ayai Tomisawa TOKYO, March 6 (Reuters) - Japan's Nikkei share average rose to a fresh 15-year high on Friday as encouraging comments from the European Central Bank lifted sentiment, but FamilyMart Co tumbled on news that it was in merger talks with UNY Group Holdings Co. The Nikkei gained 1.1 percent to 18,965.86 points