Pittsburgh-based Black Box Corp. (Nasdaq; BBOX), a cataloger of computer networking products and services, suffered a 15% drop in third-quarter sales and a 12% decline in net income. For the three months ended Dec. 29, Black Box posted net income of $14.8 million on sales of $153.2 million. For the previous fiscal third quarter, net income had been $16.9 million on revenue of $179.2 million.