Despite pledges to the contrary, the Star Tribune continues to hemorrhage print readers, according to an Audit Bureau of Circulations (ABC) report released today. During the same period, PiPress circulation was essentially flat.

The Strib lost 7 percent of subscribers on Sunday and weekdays between March 2007 and March 2008. That means 40,000 fewer people bought the lucrative Sunday paper; the drop was 24,000 on weekdays.

Here's how Sunday circulation has fallen over the past 18 months:

Sept. '06: 596,000
March '07: 574,000
Sept. '07: 570,000
March '08: 534,000

In the same period, daily circulation fell from 358,000 to 321,000.

The Strib’s Sunday decline was seventh-biggest among the nation's Top 25 papers and its daily decline was the sixth-largest. The Strib remains the 10th-biggest Sunday paper and slipped from 18th to 19th on weekdays.

Meanwhile, the Pioneer Press reported minuscule gains. From March '07 to March '08, the paper had sold 212 more Sunday readers copies and 177 additional daily readers editions. Circulation stands at 252,055 on Sunday and 191,768 on weekdays. In September '06, the numbers were 245,600 and 184,000, respectively.

[UPDATE: One reason for the marginal gain: the PiPress is counting 2,768 "e-edition" subscriptions for the first time. The e-edition lets you look at the print edition of the paper on your web browser, and costs about $60 a year.]

The Strib, of course, remains the better-read and fatter paper, but the subscriber gap is narrowing. Eighteen months ago, the PiPress' Sunday circulation was about 41 percent of the Strib's; today, it's roughly 47 percent.

Last fall, Strib circulation manager Cindy Doege said that the Strib's new zoned editions would boost circulation. Since then, the paper has consolidated geographic-specific news into a once-a-week section. I have a call into Doege and will update this story when I hear from her.

As the Strib's circulation number declines, more subscribers are receiving discounts. In September, 23,800 Sunday subscribers got 50 to 75 percent off; now, 29,990 do.

However, there are lots of ways to manipulate circ numbers. For example, the Strib has dramatically cut the so-called "other paid" category — often business-sponsored giveaways and hotel bulk purchases that yield very little revenue. Last September, 30,400 Sunday papers were vended this way; now, 6,900 are.

During the same interval, the PiPress' Sunday "other paid" number rose from 15,300 to 19,600. PiPress circ boss Andrew Mok says its tricky comparing September and March results because of seasonal discounting and promotions, and thinks his "other paid" number was flat from March '07 to March '08.

Still, in the most lucrative circ category — those paying 50 percent or more — the Strib numbers are going down while the PiPress numbers rise. Keep in mind that the PiPress is cheaper than the Strib, so it's easier for the paper to get people paying half or more of list price.