WESCO International Inc., Pittsburgh, PA, distributor of electrical MRO products and construction materials, reported sales of $1.45 billion in the first quarter 2007, up 15% from the same period a year ago. Sales from the acquisition of Communications Supply Corp., purchased in the fourth quarter 2006, were about $160 million.   ; Profit was $48.2 million, up from $44.5 million in the same period a year ago.   ; Core electrical sales rose 2%, while sales at CSC added 13% to consolidated sales revenue.   ; WESCO had 2006 sales of $5.3 billion.