Looking Like a Plastic Christmas : Retailing: Consumers have charged 21% more on their Visa cards so far this holiday shopping season.

SAN FRANCISCO — It’s beginning to look a lot like a plastic Christmas.

Visa International said consumers charged more than $9.3 billion on their Visa cards during the first nine days of holiday shopping, a 21% rise from a year ago.

Visa, the world’s largest consumer payment system, said much of that was because of a 21% increase in the number of Visa cards and an 8.2% increase in the number of merchants that accept the cards.

The biggest sales increase came in the mail- and telephone-order categories, a 24% rise to $1.1 billion. Visa said its sales at department stores were also strong, rising 12% to $891 million.

Overall, however, analysts and retailers have said holiday shopping got off to a mostly sluggish start as consumers--worried about high debt levels and job security--appear to be holding off on purchases in hopes of getting lower prices.

Last week, Mitsubishi Bank/Schroder Wertheim’s weekly report said U.S. retail same-store sales--sales at stores open at least a year--fell 0.2% for the week ended Nov. 25 on a seasonally adjusted basis, after three weeks of increases.

TeleCheck Services Inc., a check acceptance company, said same-store check sales for the Thanksgiving weekend fell 4.7% from a year ago. Checks account for about 37% of spending, compared with credit and debit cards, which account for 13%.

Also last week, the International Council of Shopping Centers said specialty store sales fell 1.3% during the first full week of the holiday shopping season compared with the year-ago period, based on a national sampling of 80 U.S. malls. Last year, the same malls reported a 4.5% sales gain. The survey does not include department stores.

In all, holiday sales are expected to rise between 3% and 5%, less than last year’s disappointing 5.2%. Some industry watchers say sales will probably be at the lower end of that expectation, judging from the slow start.