COURT BLOCKS DELTA-WESTERN AIRLINES MERGER A U.S. Appeals court last night blocked the 860 mln dlr merger of Delta Airlines Inc <DAL.N> and <Western Airlines> just hours before it was to go into effect because of a dispute over union representation. The ruling came in a lawsuit in which the Air Transport Employees union said Western's management should fulfil a promise to honour union contracts if a merger took place. The airlines argued that Western's promise could not be enforced in a takeover by a larger company. Airlines officials could not be reached for comment on the ruling, which halts the merger until arbitration on the dispute is completed.