Index: source/blender/editors/object/object_group.c
===================================================================
--- source/blender/editors/object/object_group.c (revision 48070)
+++ source/blender/editors/object/object_group.c (working copy)
@@ -160,6 +160,138 @@ void GROUP_OT_objects_remove_active(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 }
 
+static int group_add_selected_exec(bContext *C, wmOperator *op)
+{
+	Main *bmain = CTX_data_main(C);
+	Scene *scene = CTX_data_scene(C);
+	Group *group = BLI_findlink(&CTX_data_main(C)->group, RNA_enum_get(op->ptr, "group"));
+	int ok = 0, cycle = 0;
+	
+	/* Assign group to selected objects */
+	CTX_DATA_BEGIN (C, Base *, base, selected_editable_bases)
+	{
+		if (base->object->dup_group != group)
+			add_to_group(group, base->object, scene, base);
+		else
+			cycle = 1;
+		ok = 1;
+	}
+	CTX_DATA_END;
+
+	if (!ok) BKE_report(op->reports, RPT_ERROR, "No objects selected");
+	if (cycle)
+		BKE_report(op->reports, RPT_WARNING, "Skipped some groups because of cycle detected");
+	
+	DAG_scene_sort(bmain, scene);
+	WM_event_add_notifier(C, NC_GROUP | NA_EDITED, NULL);
+	
+	return OPERATOR_FINISHED;
+}
+
+void GROUP_OT_group_add_selected(wmOperatorType *ot)
+{
+	PropertyRNA *prop;
+
+	/* identifiers */
+	ot->name = "Add Selected to Group";
+	ot->idname = "GROUP_OT_group_add_selected";
+	ot->description = "Add all selected objects to an existing group";
+	
+	/* api callbacks */
+	ot->exec = group_add_selected_exec;
+	ot->invoke = WM_enum_search_invoke;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+	/* properties */
+	prop = RNA_def_enum(ot->srna, "group", DummyRNA_NULL_items, 0, "Group", "");
+	RNA_def_enum_funcs(prop, RNA_group_local_itemf);
+	ot->prop = prop;
+}
+
+/* Only add items for groups that the selected objects are in*/
+static EnumPropertyItem *group_remove_selected_itemf(bContext *C, PointerRNA *UNUSED(ptr), PropertyRNA *UNUSED(prop),
+                                                     int *do_free)
+{
+	EnumPropertyItem item_tmp = {0}, *item = NULL;
+	int totitem = 0;
+	int i = 0;
+	ID *id = C ? (ID *)CTX_data_main(C)->group.first : NULL;
+
+	/* loop through groups first */
+	for (; id; id = id->next) {
+		/* only get local groups, why? This is what is done in RNA_group_local_itemf */
+		if (id->lib == NULL) {
+			/* if this group is part of any object, add to enum list and break */
+			CTX_DATA_BEGIN (C, Base *, base, selected_editable_bases)
+			{
+				if (object_in_group(base->object, (Group *) id)) {
+					item_tmp.identifier = item_tmp.name = id->name + 2;
+					item_tmp.value = i;
+					RNA_enum_item_add(&item, &totitem, &item_tmp);
+					break;
+				}
+			}
+			CTX_DATA_END;
+		}
+		/* increment i at end for each group because the value is used to find group in the main list */
+		i++;
+	}
+
+	RNA_enum_item_end(&item, &totitem);
+	*do_free = TRUE;
+
+	return item;
+}
+
+static int group_remove_selected_exec(bContext *C, wmOperator *op)
+{
+	Main *bmain = CTX_data_main(C);
+	Scene *scene = CTX_data_scene(C);
+	Group *group = BLI_findlink(&CTX_data_main(C)->group, RNA_enum_get(op->ptr, "group"));
+	int ok = 0;
+	
+	/* Assign group to selected objects */
+	CTX_DATA_BEGIN (C, Base *, base, selected_editable_bases)
+	{
+		if (object_in_group(base->object, group)) {
+			rem_from_group(group, base->object, scene, base);
+			ok = 1;
+		}
+	}
+	CTX_DATA_END;
+
+	if (!ok) BKE_report(op->reports, RPT_ERROR, "No objects selected");
+	
+	DAG_scene_sort(bmain, scene);
+	WM_event_add_notifier(C, NC_GROUP | NA_EDITED, NULL);
+	
+	return OPERATOR_FINISHED;
+}
+
+void GROUP_OT_group_remove_selected(wmOperatorType *ot)
+{
+	PropertyRNA *prop;
+
+	/* identifiers */
+	ot->name = "Remove Selected from Group";
+	ot->idname = "GROUP_OT_group_remove_selected";
+	ot->description = "Remove all selected objects from an existing group";
+	
+	/* api callbacks */
+	ot->exec = group_remove_selected_exec;
+	ot->invoke = WM_enum_search_invoke;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+	/* properties */
+	prop = RNA_def_enum(ot->srna, "group", DummyRNA_NULL_items, 0, "Group", "");
+	RNA_def_enum_funcs(prop, group_remove_selected_itemf);
+	ot->prop = prop;
+}
+
 static int group_objects_remove_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	Main *bmain = CTX_data_main(C);
Index: source/blender/editors/object/object_intern.h
===================================================================
--- source/blender/editors/object/object_intern.h (revision 48070)
+++ source/blender/editors/object/object_intern.h (working copy)
@@ -142,6 +142,8 @@ void GROUP_OT_create(struct wmOperatorType *ot);
 void GROUP_OT_objects_remove(struct wmOperatorType *ot);
 void GROUP_OT_objects_add_active(struct wmOperatorType *ot);
 void GROUP_OT_objects_remove_active(struct wmOperatorType *ot);
+void GROUP_OT_group_add_selected(wmOperatorType *ot);
+void GROUP_OT_group_remove_selected(wmOperatorType *ot);
 
 /* object_modifier.c */
 void OBJECT_OT_modifier_add(struct wmOperatorType *ot);
Index: source/blender/editors/object/object_ops.c
===================================================================
--- source/blender/editors/object/object_ops.c (revision 48070)
+++ source/blender/editors/object/object_ops.c (working copy)
@@ -108,7 +108,9 @@ void ED_operatortypes_object(void)
 	WM_operatortype_append(GROUP_OT_objects_remove);
 	WM_operatortype_append(GROUP_OT_objects_add_active);
 	WM_operatortype_append(GROUP_OT_objects_remove_active);
-
+	WM_operatortype_append(GROUP_OT_group_add_selected);
+	WM_operatortype_append(GROUP_OT_group_remove_selected);
+	
 	WM_operatortype_append(OBJECT_OT_delete);
 	WM_operatortype_append(OBJECT_OT_text_add);
 	WM_operatortype_append(OBJECT_OT_armature_add);