** Shares of Eclipse Metals EPM.AX fall 16.67% to A$0.005
** Stock hits lowest level since March 25
** Mineral explorer says it has been served a writ of summons and a commercial list statement by Pioneer Resources Partners LLC
** Writ of summons regarding commercial contractual disputes claim against co in the Supreme Court of New South Wales, says co
** EPM denies claim by Pioneer Resources Partners LLC
** Stock down 16.7% YTD
(Reporting by Sherin Sunny in Bengaluru)
((Sherin.Sunny@thomsonreuters.com))