Starbucks expresses confidence in rewards overhaul

NEW YORK (AP) — Starbucks expressed confidence Thursday that an overhaul of its rewards program will drive up sales over the long term, but warned that the transition could be bumpy.

The Seattle-based chain said global comparable sales rose 6 percent, including a 7 percent increase in its flagship U.S. market.

The change in the U.S. went into effect just last week, with people earning rewards "stars" based on the amount of money they spend, rather than how often they visit.

The company reaffirmed its fiscal 2016 financial targets and said its board authorized the repurchase of another 100 million shares of stock, raising the total number of shares available for buybacks to 125 million.