By Sruthi Ramakrishnan (Reuters) – SodaStream International , the Israeli at-home soda machine maker said to be looking for a buyer, estimated third-quarter revenue below market expectations, raising fears that weak results could put off potential suitors. The company’s U.S.-listed shares fell as much as 22 percent on Tuesday to $21.61, the lowest since the stock’s debut in November 2010. Sales of the company’s soda machines have remained weak in the United States as consumers in the company’s biggest market opt for healthier drinks such as juices and teas over sodas. …