NEW YORK, United States — Online shopping surged to a record on Cyber Monday as many consumers snubbed physical stores and took to the Web to buy holiday gifts.

Internet retail sales on the Monday after Thanksgiving rose 18 percent from a year ago to $1.74 billion, making it the heaviest Web-spending day ever for the fourth consecutive year, according to researcher ComScore Inc. More than $23.9 billion has been spent on the Web since Nov. 1, an 8.4 percent gain from the same period in 2012, the company said in a statement.

Cyber Monday marked a bright spot in a holiday shopping season that so far has lacked luster, including the first spending decline for a Black Friday weekend since 2009. While e-commerce is projected to make up only about 14 percent of total retail sales in November and December, companies such as Amazon.com Inc. and EBay Inc. are luring customers with the promise of daily deals, fast shipping and the ease of leaving the minivan in the driveway. They’re also catering to consumers who are browsing products from tablets and smartphones.

“Cyber Monday itself continues to be the most important day of the online holiday shopping season,” ComScore Chairman Gian Fulgoni said in a statement.

Businesses across the retail industry showed increased sales on Cyber Monday. Visa Inc., the world’s biggest bank-card network, said U.S. cardholders spent $7.8 billion from Thanksgiving through yesterday, a 30 percent increase from a year earlier. On Cyber Monday, Visa customers spent $2.6 billion, up 28 percent and the most of any day during that span.

Walmart.com Record

Wal-Mart Stores Inc., the world’s largest retailer, said yesterday was its biggest-ever online spending day, and that Thanksgiving to Cyber Monday marked the company’s highest five- day Web sales period to date. Top-selling items on Cyber Monday included an LG 50-inch television, Apple Inc.’s iPad 2 and a Fisher-Price Power Wheels truck.

“The momentum we saw on Thanksgiving carried through to Cyber Monday,” Joel Anderson, president of Walmart.com in the U.S., said today in a statement.

Amazon’s Cyber Monday same-store sales jumped 46 percent, while EBay’s climbed 32 percent, according to ChannelAdvisor Corp., which provides services to sellers on both of those sites. EBay’s PayPal unit said in a statement that mobile payment volume more than doubled as of 2 p.m. New York time yesterday compared with a year earlier.

Retailers who tailored applications and websites for smartphone and tablet users benefited from the effort. Mobile traffic accounted for 32 percent of site visits, a 45 percent gain from a year earlier, according to International Business Machines Corp. In terms of sales, mobile devices drove more than 17 percent of online purchases on Cyber Monday, IBM said.

Groupon Mobile

Such devices also helped make Black Friday and Cyber Monday the two biggest sales days in North America in Groupon Inc.’s history, the company said in a statement today. Transactions made on smartphones or tablets made up 55 percent of sales for the four-day weekend. Bookings rose 30 percent in that period, Groupon said.

Wayfair LLC, which began selling home furnishings on the Web in 2002, posted a 50 percent increase in Cyber Monday sales, marking the biggest revenue day in the company’s history. From Thanksgiving through yesterday, the store saw $25 million in revenue, a 56 percent rise from a year earlier.

Web-based retailers are reporting strong sales even as those with physical stores face a less rosy holiday shopping season. Online spending increased 15 percent to a record $1.2 billion on Black Friday, according to Reston, Virginia-based ComScore. At the same time, because of the in-store slump, total purchases fell 2.9 percent to $57.4 billion during the four days beginning with the Nov. 28 Thanksgiving holiday, according to a survey commissioned by the National Retail Federation.

“The real winners are, in fact, the consumers, who are recognizing more savings through competitive pricing and great promotions being offered in every category,” NRF Chief Executive Officer Matthew Shay said in a statement.

By Danielle Kucera; Editors: Jillian Ward, Pui-Wing Tam