British private equity fund Permira will buy 20 percent of casino operator Galaxy Entertainment Group Ltd for USD 838 million, the Hong Kong firm said on Thursday, getting in on a Macau gambling boom. Permira will buy 452 million shares from Galaxy shareholder K.Wah International Holdings Ltd for USD 490 million, and acquire another 323 million new shares from Galaxy for USD 348 million, Galaxy said in a statement on Thursday.