CHICAGO (Reuters) - More US consumers say job concerns are causing them to spend less on the holidays this year and the majority are still waiting for big discounts to finish their Christmas shopping, a new survey said.

Thirty-eight percent of the people surveyed by America's Research Group said that concerns about keeping or getting a job were causing them to spend less this holiday season.

That compares with about 26 percent of people who said a year ago that job concerns were causing them to spend less on holiday shopping, said Britt Beemer, founder of America's Research Group, a consumer research and marketing firm.

The number has held around the 38 percent level since early September, Beemer said, noting that people worried about their jobs could cut their holiday spending by one-third to one-half.

At the same time, consumers are holding out for big deals, as 58 percent said they are waiting for larger discounts later in the season to finish their holiday shopping.

With Christmas on a Friday this year, those consumers may wait until even after the Saturday before Christmas, putting a crimp in what is traditionally one of the busiest shopping days before the holiday.

"They are getting worried that big discounts won't happen until the Monday before Christmas," Beemer said of shoppers.

The survey was conducted Saturday and Sunday with questions supplied by Reuters. One thousand people responded and the survey has an error factor of plus or minus 3.8 percent.

While retailers have tightened inventories this year in order to avoid the desperate discounts they took last year during the height of the recession and the credit crunch, only 32.5 percent of consumers said they found retailers were running out of more items this year than last year.

Beemer said that number would have to be above 50 percent before he would be concerned that retailers were running out of a lot of items.

Consumers also continued to pay with cash this year. Only 23 percent of the 796 consumers who shopped over the weekend said they used credit cards to pay, down from 33 percent a year earlier.