Wall Street closes a record-breaking week

NEW YORK — Wall Street closed its third winning week in the last four with a quiet finish on Friday. The S&P 500 edged down by a whisper, less than 0.1 per cent, after setting its all-time high the day before. The Dow Jones Industrial Average fell 142 points, or 0.3 per cent, and the Nasdaq composite edged up by less than 0.1 per cent to add its own record. Norfolk Southern chugged 2.5 per cent higher after an AP source said it's talking with Union Pacific about a merger to create the largest railroad in North America, one that…