The world's biggest retailer, Wal-Mart Stores Inc, on Thursday posted a 3.7 per cent rise in October same-store sales and said total sales soared 11.3 per cent to $18.4 billion from $16.6bn in the year-ago period. The Arkansas-based company said in a statement apparel sales at the start of the month were slow but picked up during colder weather and are now back on track for the season.