DineEquity Inc. Chief Executive Julia Stewart will step down from her role effective March 1, the Glendale restaurant group announced Friday. Richard Dahl, chairman of the company’s board of directors, will serve as interim chief executive while DineEquity hunts for her replacement.

“For more than 16 years, Julia has been a strong and valued leader of DineEquity and the IHOP and Applebee’s brands,” Dahl said in a prepared statement. “Under (her) leadership, DineEquity has become one of the largest full-service, fully franchised chains in the world.”

Stewart’s tenure as leader of the company began in 2002, when she was appointed chief executive of IHOP restaurants. She is credited with revitalizing the brand through re-franchising as well as with engineering its $2.1 billion merger with Applebee’s Bar & Grill, which resulted in DineEquity’s formation in 2007.

Yet the company recently has been weighed down by its struggling Applebee’s restaurants, sales at which have failed to improve consistently since 2011 despite significant marketing overhauls that have included installing wood-fired grills at all 2,000 U.S. locations. In its press release about Stewart’s resignation, DineEquity said preliminary analysis of full-year results for fiscal 2016 indicated that same-restaurant sales fell 0.1 percent at IHOP and 5 percent at Applebee’s, compared to a year ago.

DineEquity will release final fourth-quarter and fiscal year 2016 report on March 1.

Shares of DineEquity (DIN) closed down $6.41, or nearly 10 percent, to $60.14 on the New York Stock Exchange.