Analyst Steven T. Kron upgraded the shares to "Buy" from "Neutral" and said he sees "multiple drivers to maintain strong top-line momentum and rising operating margins in 2008."

Kron said the chain's new products -- like Apple Fries, burger sliders and chicken salads -- store remodels and extended hours all will likely lead to better same-store sales, or sales at locations open at least a year.

Same-store sales is a key indicator of restaurant performance since it measures growth at existing locations rather than newly-opened ones.

The sales have allowed the Miami company to grow its margins -- an accomplishment "few have been able to achieve given the sluggish consumer and cost inflation."

Consumers have been struggling to pay higher food prices at both supermarkets and restaurants as manufacturers and restaurant chains look to offset higher commodity costs. High gas prices and the weak housing market have left consumers even more concerned about spending.

Kron noted that quick-service restaurants, which offer lower prices, are the best investment in the restaurant sector in the current consumer environment.

The analyst also said Burger King's first analyst meeting in February could "garner more investor enthusiasm" since the company plans to showcase its Mexico City operations.

Burger King shares rose 91 cents, or 3.4 percent, to $28.05 in midday trading. Earlier the stock traded at $28.50, surpassing its 52-week range of $19.02 to $27.93.