Online spending rose at the slowest pace on record in the holiday shopping season from Nov. 1 to Dec. 21 as discounts cut into retailers’ profits and consumers tightened their wallets in the wake of high gasoline prices, Bloomberg reported.

U.S. Internet sales rose to $26.3 billion, a 19 percent increase from the same period a year ago, according to ComScore Inc. This is below last year’s growth of 26 percent and the Virginia-based research firm’s prediction for a 20 percent gain this year. ComScore has not recorded a growth rate less than 20 percent since it began tracking online sales figures in 2002.

Many consumers are making holiday purchases later this season. Sales soared 25 percent in the five days through Dec. 21, compared with the same period last year. However, experts believe the late surge won’t make up for lackluster sales earlier in the holiday shopping season.

Stock prices of U.S. retailers have dropped recently, with the Standard & Poor’s 500 Retailing Index falling 10 percent since the start of November compared with a 4.2 percent decline in the S&P 500.