NEW YORK — Shoppers came out again to seriously shop last week, after taking breather from a record spending spree over the Thanksgiving weekend, according to one measure

Sales at stores opened at least a year rose 3.4 percent for the week ended Saturday compared with the previous week, according to the International Council of Shopping Centers-Goldman Sachs Weekly Chain Store Sales Index, released Tuesday.

That follows two consecutive weekly declines, compared with the previous weeks, as shoppers took a break after a discount-fueled spending spree over the Thanksgiving weekend, the official start of the holiday shopping season.

Compared with a year ago, sales for the week rose 4.6 percent.

"Consumers were out in force this past week trying to complete their holiday shopping," said Michael P. Niemira, chief economist at the International Council of Shopping Centers.

And there's still more shopping to do. According to a poll of 1,000 shoppers conducted by ICSC and Goldman Sachs, shoppers on average completed 70 percent of their holiday buying as of Sunday. That compares with 74 percent at the same time a year ago. Moreover, 9 percent of shoppers polled hadn't even started their holiday buying, up from 6 percent last year.

The weekly index is a sales proxy for 24 major stores, including Target Corp, Costco Wholesale Corp. and Macy's.

Niemira still expects revenue at stores opened at least a year for his monthly tally of retailers to be up anywhere from 3.5 percent to 4.0 percent, following a revised 2.8 percent increase in November. Overall, he's predicting the measure to be up 3.5 percent for the combined November and December period. That's considered a healthy increase but less than the 3.8 percent pace seen during the holiday 2010 period.