Index: data/class/pages/admin/products/LC_Page_Admin_Products_ProductClass.php
===================================================================
--- data/class/pages/admin/products/LC_Page_Admin_Products_ProductClass.php	(リビジョン 23289)
+++ data/class/pages/admin/products/LC_Page_Admin_Products_ProductClass.php	(作業コピー)
@@ -512,6 +512,11 @@
             }
         }
 
+        // 登録済みの規格を先頭に並べる。
+        $del_flags = array_map(function ($class) { return (int)$class['del_flg']; }, $arrMergeProductsClass);
+        $indexes = array_keys($arrMergeProductsClass);
+        array_multisort($del_flags, SORT_NUMERIC, SORT_ASC, $indexes, SORT_NUMERIC, SORT_ASC, $arrMergeProductsClass);
+
         // 登録済みのデータで上書き
         $objFormParam->setParam(SC_Utils_Ex::sfSwapArray($arrMergeProductsClass));