UPDATE 1 — EU antitrust regulators set to block UPM — Sappi merger, sources say
(Adds details from third paragraph) BRUSSELS, Sept 18 (Reuters) — Finland's UPM-Kymmene and South Africa-listed Sappi are set to face an EU antitrust veto against their proposed €1.42 billion ($1.66 billion) paper joint venture after the companies declined to offer concessions to address competition concerns, people fa