BUZZ-Shares in Walmex drop despite growth in December sales

** Shares in Wal-Mart de Mexico, the country's biggest retailer, drop by about 1.8 pct despite growth in December sales

** Analysts see little upside potential in stock price due to high valuations

** Shares of Walmex are quoted at an estimated P / E multiple for 2018 of 38.2 times compared to 16.8 times the S&P BMV IPC index, according to Banorte-Ixe

** Shares of Walmex hit a record intraday high of 48.59 pesos at the beginning of this year (Reporting by Skeky Espejo)