Chipotle’s (CMG) salsa may be hotter than its stock.

The chain of “quick-casual” Mexican eateries says it expects profit to decline in the third quarter and slashed its full-year sales outlook to reflect the weak US economy.

Shares in the company lost 18.76% in late morning trading and recently fetched $57.80 each, falling below a 52-week low of $65.15. The 52-week high is $155.49.

Chipotle, which operates about 700 restaurants in 30 states, says it now expects comparable store sales to increase in the mid-to-low single-digit percentages in 2008. Previously, the company said it expected the increase to be in the mid-single digits.

The company expects third-quarter earnings to be slightly below last year’s $0.62 per share.

Apparently, more workers are brown-bagging it as the economy sours and are eating out less frequently. Restaurants are also boosting prices to reflect rising costs.

Nevertheless, Chipotle says it plans to open as many as 140 new restaurants this year.

Chipotle opened its first restaurant in 1993 and became a subsidiary of McDonald's (MCD) in 1998. Chipotle launched its IPO in 2006.

Chipotle’s competitors include Panera Bread (PNRA), Qdoba Restaurant, operator of Qdoba Mexican Grill, and Einstein Noah Restaurant Group (BAGL).

For more on Chipotle, check out Hoofy and Boo's always astute report: