Starbucks posts bigger-than-expected drop in global sales

April 29 (Reuters) - Starbucks SBUX.O posted a bigger-than-expected drop in quarterly global comparable sales on Tuesday, as demand remained sluggish for its pricey coffees in the United States amid rising macroeconomic uncertainty.

The company reported total same-store sales decline of 1% for the second quarter, compared with analysts' average estimate of a 0.26% fall, according to data compiled by LSEG.

"Our financial results don't yet reflect our progress, but we have real momentum with our "Back to Starbucks" plan. We're testing and learning at speed and we're seeing changes in our coffeehouses," CEO Brian Niccol said in a statement.

Niccol has sought to revive sales by steering the company to its coffeehouse roots but his efforts face an increasingly cautious consumer dealing with the fallout of U.S. President Donald Trump's erratic trade policy.

North America same-store sales fell 1%, compared with estimates of a 0.24% drop.

Starbucks has also struggled with weak demand in China, its second largest market as cheaper local alternatives chip away its market.

Sales in Greater China were flat following four straight quarters of decline.

International comparable sales rose 2%, compared with estimates of a 1.13% drop.

Gross margin fell 590 basis points in the quarter and the company reported adjusted earnings per share of 41 cents, compared with estimates of 49 cents.