Chipotle Mexican Grill Inc on Thursday reported quarterly sales that missed analysts' estimates, and shares fell 10.5 percent.

Sales at established restaurants, open at least 13 months, were up 8 percent, less than the 10.1 percent gain analysts had expected, according to Consensus Metrix.

The company said same-restaurant sales growth came from menu price increases, most of which were taken in 2011, as well as from increased customer traffic.

Chipotle, one of the restaurant industry's best-performing names, said second-quarter profit at the upscale burrito chain grew more than 61 percent to $81.7 million, or $2.56 per diluted share.

Analysts, on average, expected a profit of $2.30 per share, according to Thomson Reuters I/B/E/S.

Revenue for the quarter was $690.9 million, up almost 21 percent.

Chipotle forecast mid-single-digit percentage growth in sales at established restaurants for the full year and guided to an effective tax rate of about 39 percent.

Chipotle has been an investor favorite, largely due to its ability to hold down labor costs while growing at an astonishing rate. It competes with Jack in the Box Inc's Qdoba burrito chain. Taco Bell, Yum Brands Inc's Mexican-inspired fast-food company, this month debuted its "Cantina Bell" menu across the United States.

Shares in Chipotle, which was spun out of McDonald's Corp in 2006, dropped 10.5 percent to $361.29 in extended trading.