PureCircle warns on first quarter profit; shares tumble

(Reuters) - Sweetener maker PureCircle Ltd said the detainment of shipments of its low-calorie sweetener stevia in the U.S. would lead to a 14 percent drop in first-half group sales. In June, U.S. Customs and Border Protection (CBP) had seized shipments of stevia extracts brought into the country by PureCircle from China after it obtained information that they are produced by convict labour. Shares in the company tumbled more than 18 percent to trade at 205 pence each on the London Stock Exchang