Mario Longhi, the Tampa-based head of North America long steel operations for Brazilian steel maker Gerdau, left the company effective Wednesday, the company said, without disclosing details about his departure. Longhi, 57, will be replaced by Guilherme Gerdau Johannpeter, a member of the family that has controlled the steelmaker for more than a century. Johannpeter will work out of Tampa and report directly to Gerdau's chief executive, his cousin Andre B. Gerdau Johannpeter. Guilherme Gerdau Johannpeter, 39, has held multiple posts since joining the company in 1985, most recently serving as vice president of Gerdau Special Steel North America. Company spokesman Philip Bell declined to discuss what prompted the change. "We can't say much, other than this was a business decision by Gerdau." Until recently, the North American unit of Gerdau was called Gerdau Ameristeel, a name that reflected its American heritage before Ameristeel and Gerdau-owned Co-Steel completed a merger in 2002. In May, the company rebranded itself globally as Gerdau. Gerdau has 45,000 employees worldwide, including 450 in Tampa.