Ahead of the Bell: Hurricane Ike hurts restaurants

In a client note Friday, William Blair & Co. analyst Sharon Zackfia expects a gas shortage over the past two weeks in the Southeast will "likely exacerbate a likely lousy quarter" for Sonic Corp., Panera Bread Co., Starbucks Corp., PF Chang's China Bistro Inc., Cheesecake Factory Inc., Chipotle Mexican Grill Inc., and BJ's Restaurants Inc.

Zackfia also cited a Fourth of July calendar shift and high viewership of the Olympics and political conventions.

Separately, Morgan Keegan analyst Destin M. Tompkins lowered his earnings-per-share estimates for Cheesecake Factory, P.F. Chang's, Chipotle, California Pizza Kitchen Inc., Red Robin Gourmet Burgers Inc., Texas Roadhouse Inc., and Ruby Tuesday Inc. based on his expectation for weaker same-store sales and operating margins. Same-store sales is an industry metric that measures sales at stores open at least one year.

"We believe volatile September sales will likely put the finishing touches on an already ugly third quarter," Tompkins wrote in a client note.

Restaurant companies have struggled to post robust growth as consumers have scaled back on spending amid a softening labor market, higher gas prices, and tighter credit.