San Diego, CA -- (SBWIRE) -- 05/09/2012 -- An investigation on behalf of investors of NYSE:ACI shares over possible securities laws violations by Arch Coal Inc was announced and NYSE:ACI stockholders should contact the Shareholders Foundation. Read the full press release at http://www.sbwire.com/press-releases/arch-coal-inc-nyseaci-investor-alert-investigation-over-potential-violations-of-securities-laws-141407.htm