 Arconic Corp. ARNC, -3.12 shares fell in after-hours trading Wednesday after executives trimmed the aluminum companys annual outlook due to production issues and European energy costs. The stock declined 8 in the extended session after executives reduced their annual revenue forecast to a range of 9.2 billion to 9.5 billion, after previously stating 9.6 billion to 10 billion, and said yearly adjusted Ebitda would be 715 million to 765 million, down from an earlier range of 820 million to 870 million. 