By James Davey LONDON (Reuters) – Primark, the fast-growing clothing chain owned by Associated British Foods , is to enter the United States, it said on Wednesday, becoming the latest British retailer to attempt to crack the American market after success in Europe. Shares in AB Foods rose 9.1 percent on the back of the U.S. initiative, a small rise in first half profit and reiteration of full-year guidance. AB Foods said Primark, which currently trades from 271 stores in nine countries in western Europe, will open its first U.S. store in Boston, Massachusetts, towards the end of 2015. Negotiations are under way to open more stores in the north east of the U.S. through to the middle of 2016.