The sales slump at Irvine-based Taco Bell Corp. is showing signs of a turnaround, according to parent Yum Brands Inc.

Louisville, Ky.-based Yum Chief Executive David Novak said Taco Bell finished 2011 with a 2% decline in same-store sales at U.S. stores but saw an upturn late in the year.

Novak told analysts Tuesday he is optimistic that Taco Bell’s sales momentum will continue this year.

The chain recently launched its First Meal breakfast menu with the hope of driving morning sales in the same way it nabbed late-night business with its Fourthmeal menu.

Taco Bell now begins serving breakfast starts at 8 a.m. and could start earlier based on demand, Novak said.

The chain also plans to launch its Doritos Locos Taco, with a shell made out of Doritos chips, next month.

Taco Bell struggled last year under the weight of rising food costs and the lingering effects of a lawsuit filed last January against the chain, challenging the content of its beef. The lawsuit was later dropped.