Retail sales fell for the third consecutive month in June, the first time sales have slumped for that long since the height of the recession. Total retail sales declined 0.5 percent from May, the Commerce Department reported in Washington Monday. Sales were down in the majority of retail categories, led by a 1.8 percent decline in spending on gasoline, as fuel prices continued to fall. Large declines in spending also registered in furniture, electronics, appliances and building supplies. The…