Independent Atlanta restaurants pushed through the second quarter with strong sales increases, according to a recent survey by Atlanta accounting firm NetFinancials. But separate data show times remain troubled for independent restaurants around the country.

In Atlanta, sales at restaurants open at least a year rose 7.2 percent from the same period in 2010. That increase came on the heels of a strong first quarter, in which sales rose 5.3 percent. The survey spanned fast food, casual restaurants and fine dining.

Due to their small size and private ownership, such restaurants do not publicly report financial results. NetFinancials generated its figures through a survey of 69 Atlanta restaurants, 80 percent of which reported sales gains for the second quarter. About one-third said they posted double-digit increases. One in five reported a drop in sales.

Robert Wagner, president of NetFinancials, said it was "a little surprising" that local restaurants were able to grow at the reported rates despite a very hot May and June and the lackluster economy.

"Even with indicators pointing to a potential slow-down, the Atlanta restaurant industry powered right through this tough period with remarkably strong, broad-based sales," he said.

A number of concepts are expanding in Atlanta. Meat-based concepts including Smashburger and Grindhouse Killer Burgers recently opened new locations and are looking to add more.

"I’m looking all over town," said Alex Brounstein, who founded the original Grindhouse at the Sweet Auburn Curb Market.

Nationally, independent restaurants suffered the steepest decline in their ranks since 2001. In the year ending in March, the nation lost 8,650 independent restaurants, or 3 percent of the total, according to Chicago-based research firm NPD Group. The number of chain restaurants stayed relatively stable.

"A volatile economy, more frugal consumers, and a lack of financial backing have made it a difficult business environment for independent restaurants," said Greg Starzynski of NPD.

The data is mixed, however. The declines in traffic that restaurants have suffered for several years are improving. For the year ending in May, visits to U.S. restaurants -- including fast-food and high-end restaurants -- were stable compared to the year before, when visits fell 3 percent. Diners' spending at restaurants grew 2 percent for the 12-month period ending in May, compared to a 1 percent drop in the same period a year before.