WASHINGTON - Black Friday and Thanksgiving online sales in the US rose to record highs, while brick-and-mortar store traffic fell slightly, heralding divergent trends in retail industry in the year-end shopping season, according to retail analytics firms on Sunday.

The online sales on Black Friday and Thanksgiving rose to 7.9 billion dollars, a record high, and up 17.9 percent from a year ago, said Adobe Analytics in a latest report, which covers transactions at the largest 100 U.S. online retailers.

Cyber Monday, the Monday after the Thanksgiving, is expected to rake in 6.6 billion dollars in online sales, making it the biggest U.S. online shopping day in history, said the report.

The sales data for traditional brick-and-mortar stores is still unavailable. The National Retail Federation (NRF) said fair weather across much of the nation had helped draw shoppers into stores. NRF will release its data of Thanksgiving, Black Friday and Cyber Monday on Tuesday.

Preliminary data tracking shoppers' visits to physical stores on Thanksgiving Day and Black Friday shows a year-over-year decline of 1.6 percent, according to retail research firm ShopperTrak.