The coffee chain is piloting a new store design, simplifying its menu, and trying other tactics to bring back customers.

The C.E.O., Brian Niccol, said the coffee chain’s turnaround was in progress, and sales in China increased for first time in more than a year.

Starbucks reported a bigger-than-expected fall in third-quarter global comparable sales on Tuesday, as the coffee chain operator grappled with waning demand in a cautious consumer spending environment.