Dell Inc. (NASDAQ:DELL), the No. 3 PC maker, may be about to embark on a $24.4 billion new chapter if it becomes a private company. But the change may not make much difference to the global PC sector, which is already declining, analysts said.

The reason is that, compared to dozens of PC vendors that competed back when a teenage Michael S. Dell founded the Round Rock, Texas, company in his dorm at the University of Texas and started to sell by mail order, now that he’s 47, the industry has radically changed.

The top six PC vendors last year accounted for 59 percent of the entire 2012 PC market of 352.7 million units, Mikako Kitigawa, principal analyst for Gartner (NYSE:IT), one of the top market research firms, said. Dell’s share was 37.6 million, down more than 12 percent from 2011.

Going private with cash from Dell himself, Silver Lake Partners and Microsoft Corp. (NASDAQ:MSFT), the No. 1 software company, won’t make much difference as far as the trend goes. As well, the deal leaves the founder atop the company as CEO, albeit with the extremely close assistance of Egon Durban, 38, a Silver Lake managing partner.

“Tablets have dramatically changed the landscape,” said Kitigawa, who noted Dell hardly has a presence in the sector, which is dominated by developers including Apple Inc. (NASDAQ:AAPL), the most valuable technology company, and Samsung Electronics Corp. (KRX:005930).

Going private may ease Dell’s transition into tablets and out of PCs, should it decide on it. Tuesday’s going-private announcement made no indication of future strategy, although more may be forthcoming when Dell reports fourth-quarter results in two weeks.

Even Apple, of Cupertino, Calif., isn’t thriving in the PC sector. It reported sales of iMacs for the quarter ended Dec. 31 fell 21 percent to only 4.1 million. That’s less than half of the estimated 9.2 million units Dell sold in the same period, according to Gartner estimates.

Meanwhile, as prices of semiconductors and electronics have declined, the biggest PC company now is China’s Lenovo Group (PINK:LNVGY), the No. 1 PC maker, which acquired the PC lines of International Business Machines Corp. (NYSE:IBM), the No. 2 computer company.

Gartner's Kitagawa said Lenovo and other Chinese vendors like Asustek Computer (TPE:2357) can work with razor-thin profit margins but not Dell. "Not even under private ownership," she said.

Lenovo’s 2012 shipments rose 14 percent to 52.2 million, Gartner said, only slightly behind Hewlett-Packard Co. (NYSE:HPQ), the No. 1 computer company. That helped send Lenovo’s third-quarter net income up 34 percent to $205 million, or $1.99 per share.

But PCs are only 30 percent of the Chinese maker’s revenue, with the rest coming from tablets and consumer electronics such as TVs and smartphones. Unlike Dell, Lenovo isn’t a factor in software and services.

Dell now derives about 70 percent of revenue from PCs, laptops and monitors related to PCs, Shaw Wu, an analyst with Sterne Agee, said. “This is progress from 85 to 90 percent in the early 2000s,” he said, “but proves it’s a slow transition.”

Dell appears intent on shifting more to higher-margin services and software ahead but hasn’t explicitly declared that strategy. Other technology giants, headed by Cisco Systems Inc. (NASDAQ:CSCO), the No 1 provider of Internet products, have completely refocused on so-called software-defined networks.

Not that long ago, Dell positioned its consumer marketing campaign around symbols such as the “Dell dude,” the young pitchman in a green costume who’d shout to people “Hey, dude, you’re getting a Dell!” Or there was another slogan asking consumers, “Can we build one for you?”

Last year, Dell’s advertising was far more restrained. Its ad agency, WPP (NASDAQ:WPPGY), focused on “More You” and “The power to do more” to elevate the brand.

As a private company, management will be able to spend whatever it wants on sales and marketing, without having to worry about pleasing analysts and shareholders every quarter. That could work both ways, though, if Silver Lake’s Durban casts a veto, as he may have on all matters at the new Dell.

Of course, Dell might want to make a play into the smartphone business, where partner Microsoft is making a big gamble. Besides its two-year-old alliance with Nokia Oyj (NYSE:NOK) of Finland, Microsoft now plans to work closely with partners including China’s Huawei Technologies on its 4Afrika plan to get millions of cheap mobile phones into African consumer hands.

With a $2 billion investment in Dell, Microsoft might want it to enter that market, as well. But it’s new territory.

Dell shares rose 15 cents to close at $13.42 in Tuesday trading. The buyout price is $13.65 per share.