Bentonville, Ark. — Walmart has reported that its third-quarter e-commerce sales grew 79 percent from the same period a year ago. Comparable sales, defined as those from stores that operated during the entire 12-month fiscal year, went up 6.4 percent. The Bentonville-based retailer’s revenue during its fiscal third quarter reached $134.7 billion, a 5.2 percent increase over the same time period a year ago. Walmart’s third quarter ended on Oct. 31.