Seattle's two daily newspapers reported small gains in weekday circulation Monday, bucking industrywide trends and their own recent history.

The Seattle Times' average paid weekday circulation for the six-month period that ended Sept. 30 was 215,311, up 1.2 percent from the same period in 2006, according to the Audit Bureau of Circulations (ABC).

The Seattle Post-Intelligencer's weekday circulation grew 1.1 percent, to 127,584.

The P-I last reported an increase in 1998, The Times in 2003.

Average circulation for the combined Sunday newspaper continued its long slide, however, dropping 0.6 percent to 420,587.

Elsewhere, 21 of the nation's 25 largest newspapers reported weekday circulation declines. The biggest drops came at The Atlanta Journal-Constitution (9.1 percent), The San Diego Union-Tribune (8.5 percent), and The Dallas Morning News (7.7 percent).

Newspaper print circulation has been plummeting in part because of competition from the Internet.

But publishers, concerned about losing advertisers, maintain that doesn't necessarily mean their total audience has shrunk as drastically.

To help flesh out that argument, ABC, with the Newspaper Association of America and New York-based Scarborough Research, on Monday unveiled for the first time estimates of total local audience — print and online — for about 200 newspapers, including The Times and P-I.

Supplemental numbers provided by Scarborough indicate The Times/P-I Web network's audience in a 17-county region has grown about 30 percent since 2005, while each paper's print readership has remained fairly stable.

The Times and P-I are partners in a joint-operating agreement (JOA). They maintain separate newsrooms, but The Times handles advertising, circulation and production — including back-end Web operations — for both papers.

Times Vice President Jill Mackie attributed both papers' increases in print circulation to new initiatives to retain customers and to the demise of the Kent-based King County Journal. That daily, which circulated in eastern and southeastern suburbs, folded in January after years of losses.

The two Seattle papers' jump in combined print circulation — about 4,000 — is a fraction of the 39,000 daily circulation the Journal reported last fall. Peter Horvitz, who sold the Journal two months before it closed, said the numbers don't surprise him.

About half the Journal's former readers also bought the Times or P-I, he said: "I don't view it as a negative."

Mackie said the Times is not disappointed. "Over time, more people will recognize the value of what we bring to the table," she said.

P-I Publisher Roger Oglesby agreed. Considering what's happening industrywide, "it's good to see some positive numbers," he said. "It's been a long time."

Black Press, which closed the Journal after buying it from Horvitz, has beefed up or established free non-daily papers in communities where the Journal once circulated. That may have kept the Times' and P-I's gains down, said Doug Underwood, a University of Washington journalism professor and former Times reporter.

The ABC numbers indicate circulation among Times and P-I readers who pay all or most of the full price of the paper actually declined this year. Gains came in other categories, including deeply discounted subscriptions.

"The numbers you see are part of a long-term pricing strategy geared to increase retention, which it has," Mackie said in an e-mail.

Circulation also was boosted by new electronic editions — digital facsimiles of the print newspaper — that the Times and P-I began marketing over the past year.

Scarborough, which bases newspaper audience estimates on telephone surveys, says 48 percent of all adults in a 17-county area read The Times or P-I either in print or online, or looked at other Web sites, such as NWSource.com, that are part of the Times/P-I online network at least once during a seven-day period.

The print newspapers aren't marketed in many of those counties. In King and Snohomish counties — the newspapers' core market — they reach about 68 percent of the total potential adult audience in a week, Scarborough says.

Since 2005, the research firm says, the number of people who visit the Times/P-I Web network in the 17-county region at least once a week has increased from about 428,000 to 570,000.

According to the most recent surveys, about 14.5 percent of all adults in the region now look at The Times' Web site, while 10.3 percent look at the P-I's, Scarborough estimates.

Both figures also include viewers of smaller sites that are part of the Times/P-I network.

Eric Pryne: 206-464-2231 or epryne@seattletimes.com