Announcement took place at Microsoftās New York headquarters
LGBT rights advocates attended presidential palace ceremony
It remains unclear whether measure includes adoption
Luis LarraĆn co-founded Fundación Iguales
Gay man attacked in Santiago park on March 2, 2012
Bachelet reaffirms pledge to introduce measure this year
Accord specifically acknowledges conflictās LGBT victims
Michelle Bachelet spoke at high-level U.N. LGBT event
Vice president spoke at historic U.N. LGBT event
Countryās president supports measure