SodaStream's investors get impatient as stock declines, sales fall

New York

SODASTREAM International Ltd's promise to invigorate sales by reinventing itself as a health-conscious provider of sparkling-water machines is eliciting a response from investors: "Prove it."

The Israeli company's stock has plunged 17 per cent in New York trading from this year's high last month, compared with a 2.1 per cent drop in the Standard & Poor's 500 Index in the span. The stock tumbled a record 11 straight trading days before climbing on Friday.

The company has been struggling to replicate its European success in the US after efforts to brand itself as an alternative to Coca-Cola Co and PepsiCo Inc did not align with shifting consume…