UPDATE 1 — No breakthrough in talks at Antofagasta's striking Centinela copper mine, unions say
(Adds company statement) SANTIAGO, Oct 15 (Reuters) — Negotiations between Antofagasta Minerals and two striking unions at Chile's Centinela copper mine showed no progress on Thursday, while three workers marked their seventh day on a hunger strike. The Distrito Centinela and Minera Esperanza unions, which together rep