Mueller Industries (MLI) beat analysts' second-quarter earnings estimate, citing strong performance across its core businesses.The company said Tuesday that net income rose to $27 million, or 73 cents a share, from $9 million, or 24 cents a share, during the same period last year. Analysts had expected the company to earn 56 cents a share. Sales rose to $380.8 million from $248.2 million a year earlier. The Memphis, Tenn.-based manufacturer of construction valves, fittings and tubes said the improved performance was a function of increased product orders in both the standard and industrial product divisions, as well as improvements in European operations. Pounds of product shipped rose 13% from a year earlier. The company said their "business outlook remains good," as housing starts and commercial construction, both important markets for Mueller, should both be strong in 2004. The business outlook remains good. Interest rates have recently ticked up, the company noted, "but by historical standards are quite low." Shares of Mueller were recently up 82 cents, or 2.3%, to $36.50.