** Shares of Australia's Arafura Rare Earths ARU.AX fall as much as 11.3% to A$0.275, their lowest level since April 13
** Rare earths miner on Friday launched A$350 million ($250.39 million) placement at A$0.260 per share
** Offer price at 16.1% discount to stock's last close on May 21
** Co says placement to fund development of Nolans project in the Northern Territory
** Stock up over 8% this year, including the day's move
($1 = 1.3978 Australian dollars)
(Reporting by Rajasik Mukherjee in Bengaluru)
((Rajasik.Mukherjee@thomsonreuters.com))