UPDATE 1-Mexico retailers Oct same-store sales fall

(Adds details on sales)

MEXICO CITY, Nov 15 (Reuters) - Mexican retailers group ANTAD said on Thursday its members' same-store sales fell 0.7 percent in October compared with a 2.2 percent rise in the same month a year ago.

ANTAD, formally known as the National Association of Supermarkets and Department Stores, said the weaker reading in October was partially due to one less Sunday in the month compared with the same period in 2006.

Weekends are when most Mexican consumers do their shopping and grocery purchases.

Market leader Wal-Mart de Mexico (WALMEXV.MX), which recently rejoined ANTAD, and rival supermarket chains Soriana (SORIANAB.MX), Comerci (COMEUBC.MX) and Gigante (GIGANTE.MX) are among the association's top members.

Same-store sales are those from stores that have been open at least 12 months and are seen as the most accurate picture of retail trends.

Same-store sales between January and October are up 1.2 percent. In September, ANTAD cut its 2007 same-store sales growth forecast to 1.5 percent, from a previous view of 2.5 percent, citing a weak consumption cycle. (Reporting by Cyntia Barrera Diaz; Editing by Tim Dobbyn)