WESCO International, Inc., Pittsburgh, PA, a provider of electrical MRO products and construction materials, has acquired J-Mark Inc., Phoenix, AZ. J-Mark, with four locations in the U.S. and annual sales of $30 million, is a provider of interior products and components to the manufactured housing industry.   ; The move strengthen's WESCO's position in the manufactured housing industry. J-Mark's president and CEO said that its offshore sourcing capabilities would also be of strategic use to WESCO.   ; WESCO International's primary operating entity is WESCO Distribution, Inc. WESCO Distribution is a distributor of electrical construction products and electrical and industrial maintenance, repair and operating (MRO) supplies, and is also a provider of integrated supply services. 2006 annual sales were $5.3 billion.