CHARLOTTE, N.C. — Ruddick Corp. here said operating profit at its Harris Teeter chain was up 16.9% in the second quarter that ended April 1, to $38.2 million, vs. year-ago results. The company said results were driven by new store openings and comparable-store sales gains of 4.87% for the period. Sales increased by 12.7 to $805.6 million for the quarter. The chain opened 10 net new stores since the second quarter of a year ago, and has 12 new stores planned for this year. Through two quarters Harris Teeter posted operating profit of $73.3 million, up 11.6%, on a sales gain of 11.9%, to 1.6 billion. Comps rose 4.09% for the 26-week first half.