Best Buy Co. (BBY) has gained more U.S. market share in its business this year than anyone else as efforts to capture customers who formerly shopped at Circuit City Stores Inc. (CCTYQ) have paid off, Best Buy Chief Executive Brian Dunn said Tuesday.

"We have a track record of acquiring and retaining market share, and we believe our ability to do that is greater than ever," Dunn said during a conference call to discuss quarterly results.

Best Buy posted its 15th consecutive quarter of market-share gains during the second quarter, when U.S. market share improved nearly 3 percentage points from a year earlier and was better than the first quarter's gain, Dunn said.

Best Buy's strongest sales were in areas "where customers need help most" in connecting and integrating their gadgets - mobile phones, televisions and digital cameras, he said.

Some of the retailer's initiatives this year, such as discounts on appliances and offers of free installation for more expensive TVs, are attracting customers even though they weigh on profits, Dunn and other executives said. But they should pay off in the long run, they said.

"It's a very competitive environment that we're playing in," Dunn said. "We're going to be there on price, and it is what our people bring to it and our service offerings ... those things together give me confidence about the economics for us."

- By Mary Ellen Lloyd, Dow Jones Newswires, 704-948-9145; maryellen.lloyd@dowjones.com