A new report says sales of U.S. magazines at newsstands and other retail outlets fell 9 percent in the first six months of the year in a sign of readers trimming discretionary spending.

Although overall circulation was down just 1 percent, the larger drop in the single-copy sales figure is troubling for magazine publishers. That's because publishers typically make more from those sales than from subscriptions, which are sold at a discount so publishers can boost circulation and lure advertisers.

Single-copy sales have been steadily declining. The Audit Bureau of Circulations, an industry trade group, says that in the latest period, the 418 titles examined sold 29.8 million copies at retail outlets, compared with 32.8 million a year earlier. Overall circulation was 301 million, down from 305 million.