
Representatives for both SodaStream and Starbucks declined to comment.
In February, Coca Cola Co (KO.N) took a $1.3 billion stake in Keurig Green Mountain Inc GMRC.O, maker of the popular Keurig one-cup coffee brewer, with plans to jointly launch a home soda maker machine, prompting speculation SodaStream would pursue its own partnership with a company.
Last week, Israeli financial news daily Calcalist reported that SodaStream was in early talks to sell 16 percent of the company to a potential investor, including PepsiCo Inc (PEP.N), Dr Pepper Snapple Group (DPS.N) or Starbucks.
SodaStream shares were up 13 percent at $45.68 in midday trading, while Starbucks shares fell 0.7 percent to $70.64.