Plans for the move were first reported yesterday by the New York Observer.

The swap is really a testament to the power of Google (GOOG) and the long-tail theory: Even though Condé had been running Portfolio.com with a skeleton crew since the beginning of the year, the site was still generating four to five million page views a month, primarily because of search queries, says Condé Nast Group President David Carey. So that alone made Portfolio.com worth saving.

It will now serve as the central hub for ACBJ, a collection of 40 local business publications (including one I used to work for many moons ago). But it won’t just be an aggregator, insists ACBJ President Tim Bradbury. He intends to rebuild the site’s staff–he’s keeping two of the last Portfolio.com employees and intends to launch with a full-time editorial staff of five, plus freelancers–and pump out new content.

Bradbury says he’d “like to get the old band back together,” but I’m not sure exactly what that means. In the last few months of Portfolio.com’s life, the site was essentially a blogging platform for the excellent duo of Felix Salmon, who covered finance, and Jeff Bercovici, who covered media. But Salmon jumped ship for Reuters prior to the shutdown, so he’s presumably locked up. No word on Bercovici’s plans. But even if Bradbury can’t get those two back on board, I’m guessing there’s no shortage of applicants for full-time and contract slots.

Here’s the release:

New York, NY, May 20, 2009 – Portfolio.com will become part of the American City Business Journal’s bizjournals.com effective in July, it was announced today by Tim Bradbury, President, American City Business Journals, New Media, (ACBJ) and David Carey, Group President, Condé Nast. ACBJ and Condé Nast are units of Advance Publications.

Bizjournals.com will oversee both the editorial and business sides of the site. The Portfolio.com editorial team and sales staff will be based in New York. In addition to newly created content, the site will share content with other Condé Nast sites including Wired.com, GolfDigest.com, and WWD.com, as it did previously. The site will also be the home of the archives of all the popular content published by Portfolio’s print and digital properties over the last two years.

“We are excited about continuing Portfolio.com and including the site in the bizjournals network because we were impressed by Portfolio’s strong web presence, its clean and crisp design, and its voice in the business journalism marketplace,” Tim Bradbury, President, American City Business Journals, New Media said. “We believe our readers will benefit as the re-launched Portfolio.com will have a stronger focus on industry news and a greater mission to offer information relevant to today’s business professionals.”

On top of its existing strengths, Portfolio.com will be able to leverage the collaborative skills and insights of the more than 600 ACBJ business journalists around the country. The site now will have access to local market intelligence and work collaboratively with ACBJ newsrooms across the country, presenting the most important local insights through a national lens and making it unique among national business media.

“We knew that Portfolio.com was a highly valuable asset, with an established digital brand, strong direct navigation by users, and a solid long tail of traffic from content published over the past two years,” David Carey, Group President, Condé Nast said. “We saw ACBJ as a perfect match due to its great editorial resources in the business arena, and view this as a win for both Portfolio.com’s readers and the company.”

Condé Nast Portfolio magazine and its website Portfolio.com, launched in April 2007 and the magazine closed in April 2009. The site provided insight into the day’s top business stories, with analysis from bloggers and columnists. During those two years Portfolio.com grew to 2.8 million monthly uniques and won industry praise with awards such as the MIN:  Best of Web 2008, MIN: Hottest Launch of the Year 2007, WebAward: Outstanding Achievement in Website Development 2007, and Webby nominees in Best Business blog and Financial Services categories.

The magazine’s May issue, which is out now, will be its last. The Web site will be shuttered “in the second quarter,” the company says.

Portfolio has had its doubters even prior to its launch in 2007. Long before the advertising market cratered, critics worried that the market couldn’t support a fourth business magazine to compete with Forbes, Time Warner’s (TWX ) Fortune and McGraw-Hill’s (MHP) BusinessWeek; they also marveled at the reported $100 million budget that Condé Nast had committed to the launch.

No telling whether that bet would have paid off in a healthier market for the high-end advertising that business magazines thrive on. (But likely not: “Condé Nast made a classic mistake of spotting a consumer magazine ‘opportunity’ based on advertising and demographic considerations, not actual reader demand,” as BusinessWeek’s Jon Fine puts it). But the current market is as bad as it could get: In the first three months of 2009, magazine ad pages declined more than 25 percent, according to an industry trade group, and Portfolio’s pages dropped by more than 60 percent. Some of that drop stems from the magazine’s move to a 10-issue-a-year schedule, down from 12 a year.

But Portfolio has been suffering for quite some time. Last fall, the magazine laid off a good portion of its staff and turned its Web site into a skeleton operation. And parent Condé Nast, which also made a round of layoffs last fall, has continued to cut back this year, eliminating perks, staff and titles throughout the company. In March CEO Chuck Townsend sent out a memo warning that “as the downturn extends, we have to make additional difficult decisions to manage costs and ensure our financial well-being.”

Here’s the full statement from Carey:

Earlier today, Condé Nast announced, quite regrettably, that it is pulling back from its investment in Portfolio.

For this high-profile, 21-issue launch, the recession has helped and hurt the brand. While the unprecedented nature of these times has made business and the economy the main topic of conversation, it has also led to high levels of uncertainty and a tremendous reduction in ad spend in the five key sectors Portfolio’s business model depends on.

The company is deeply grateful to Portfolio’s readers and for the broad support of marketers and executives all around the country.

And here’s the beginning of the magazine’s obituary from soon-to-be-unemployed Portfolio.com media writer Jeff Bercovici:

For nearly two years I’ve been covering the media industry’s bad news on this blog, including some that’s hit very close to home. Now it hits closer still: Condé Nast Portfolio is closing.

Our editor in chief, Joanne Lipman, just broke the news to staff, saying the decision had been made “because of financial reasons at Advance,” Condé Nast’s parent company. “It’s not anything that the company wanted to do.” She said she was informed by Condé Nast chairman S.I. Newhouse Jr. this morning of the decision.

And here’s the press release:

Condé Nast will cease publication of Portfolio effective with its May issue and Portfolio.com will close in the second quarter of the year, it was announced today by Charles H. Townsend, President and CEO of Condé Nast.

“The pressures and realities of the continuous deep economic slump have lowered Portfolio’s revenue projections below what is needed to continue publication,” Mr. Townsend said. “Portfolio was an ambitious and innovative magazine and website, and we were proud to publish them. The challenges facing this launch however proved too great. Joanne Lipman is an extraordinarily skillful editor and William Li is a very talented publisher. We thank them and their staffs for their tremendous efforts. It is unfortunate we were unable to give Portfolio the time needed to fully mature.”

Portfolio and Portfolio.com were launched in May 2007. The magazine has published 21 issues since its launch. The magazine received a National Magazine Award in 2008 and has been nominated for multiple awards since.

Condé Nast Publications, a unit of Advance Publications, includes consumer magazines, Condé Nast Digital, the Fairchild Fashion Group, the Condé Nast Media Group, and the Shared Services Centers.

A second source says they’ve been told the staff will shrink down to three people and that a “plan would be worked out in the next couple of days.”

Also unclear: Which one of Condé’s digital units will end up adopting the Web site. Portfolio.com had been run as a standalone property. That made it a rarity at Condé, where most of magazines’ digital arms are run by its Magnet unit, and the rest are run by Sarah Chubb’s CondéNet group.

Confused? So are most Condé Nast staffers, who spend lots of time complaining about the publisher’s byzantine digital architecture. But you won’t hear them complaining too loudly right now–they’re trying to hang on to their jobs, or at least protect their exit packages.

Web site staffers were told about the cuts in a meeting led by General Manager Ari Brandt and publisher David Carey, who didn’t provide much detail, according to people who attended the meeting.

Portfolio.com staffers have been told they have been meeting their revenue goals for 2008 while the magazine has not. According to a person who attended the meeting, one of the staff’s braver souls asked Carey why the Web site was being punished more severely than the magazine.

“He gave a sort of corporate-speak answer, and what it appeared to boil down to is, is ‘This is a magazine company,’” says a person who attended the meeting. ”And it left the impression that the Web site was sacrificed to save the magazine.”

In a separate meeting, Portfolio magazine editor Joanne Lipman told her staff that the publication would cut some positions and publish 10 times a year instead of monthly.

UPDATE: A partial list of departing Portfolio staffers.

Time Warner’s Time Inc. (TWX) won’t be the only magazine publisher making cuts this fall: Condé Nast is trimming its sails, too.

The New York Observer reports that every title at the privately held publisher is being required to cut five percent from both its editorial and business ledgers, a number that MediaMemo hasn’t been able to confirm.

But I can tell you that the staff at Portfolio, Condé’s business magazine launched with equal parts fanfare and controversy last year, has been summoned to an all-hands meetings that should be starting … now. I’ll pass along more details as I get them.

UPDATE: A partial list of departing Portfolio staffers.

Recall that just two days ago Condé Nast publisher David Carey was expressing (guarded) optimism about advertising budgets next year. I’m guessing that if he were less optimistic, the cuts would be even larger.

And what about CondéNet, the Condé division that handles Web properties for some, but not all, of the publisher’s magazines? No comment, but one might imagine Sarah Chubb’s unit will be cutting back, too.

UPDATE: Condé is firing most of the staff of Portfolio.com, shrinking it from two dozen down to “single digits.”

UPDATE: I’m told that Portfolio staff has just been told the magazine will now be published 10 times a year, down from 12, and will cut five percent from its edit budget. (A second source says that will amount to 18 to 20 staffers) The December and January issues will be combined, as will the June and July issues.

UPDATE: One officially announced cut: Men’s Vogue will be shrunk down to a twice-yearly schedule. The one-paragraph release:

Men’s Vogue will be absorbed into Vogue and published in the spring and fall, it was announced today by Charles H. Townsend, President and C.E.O of Condé Nast Publications. It will continue to be edited by Jay Fielden.”

Disclosure: I’ve done freelance work for Vanity Fair.

Last year MediaMemo made some intemperate comments about paidContent’s “Future Of Business Media” conference.

But I am happy to say that I don’t have any complaints about this year’s event. (OK, I do–the Wi-Fi’s been a bit spotty.)

But lots of good speakers and thoughtful questions. I look forward to checking out Rafat Ali’s paidContent reporting to catch up on the sessions I missed from this morning.

But I can tell you about an amazing event I saw this afternoon–an optimistic magazine publishing executive, who didn’t appear visibly drunk or otherwise intoxicated.

Here’s the quote, in its entirety, from Condé Nast publisher David Carey, who was part of a panel on business magazines: “We’ve talked to a lot of clients who are surprisingly bullish about their ad spend next year.”

“Who’s that”? Forbes.com publisher Jim Spanfeller immediately asked. But David just smiled.

Remind me to follow up with Carey on that next spring.