Chris Liddell, the newly installed General Motors CFO, could be the poster boy for the portability of finance skills. Coming from tech giant Microsoft, Liddell has a sterling reputation but no direct experience with the auto industry and its various manufacturing and distribution challenges.

To be sure, Liddell may have benefited from the widespread frustration with veteran executives at GM and other automakers. But what likely got him the job (and a shot at the CEO spot, according to GM interim CEO Edward Whitacre) was the general management skills that are increasingly setting the best CFOs apart from the rest. In the press release announcing the move, Whitacre said he and the board were “looking to [Liddell’s] experience and insights in corporate strategy” to help with the automaker’s massive restructuring efforts.

“GM’s board is not asking [Liddell] to design a car or manufacture one,” says Russell Boyle, head of the financial officers practice at Egon Zehnder, noting that Liddell didn’t have any technology-industry experience before going to Microsoft. “The ability to be a change agent, to influence across the businesses, and to bring something to the table beyond the traditional analytical skills — that’s what’s really being sought after here.”

And while Liddell might stand out for the starkness of his change and the elevated profile of his new gig, Boyle says CFOs with his kind of skills cross industries “all the time,” and that it’s happening no more or less frequently during the downturn.

A number of recent CFO appointments seem to prove Boyle’s point. Former Washington Mutual CFO Tom Casey just took the same role at Clear Channel Communications with no prior media industry experience listed on his résumé, Brian MacDonald joined Sunoco as CFO from Dell, and Peter Hathaway became JDA Software’s CFO after 14 years in finance at Alliance Waste Systems.

Still, it’s fairly rare these days for large companies to take a bet on a CFO from an industry far afield of their own. CFO‘s analysis of Audit Analytics data shows that of the approximately 77 S&P 500 companies that have had a new CFO start since January 1, 2009, only 15, or about 20%, came from other industries. Even then, many of the other industries were closely related to that of the hiring company. A majority of companies, in fact, preferred to stick with a known quantity and promote from within; only 40% of new CFOs came from outside the company.

Why can it be so hard for some finance executives to switch sectors? Often, boards and CEOs may simply be wary of taking chances. “Finance skills travel, but what I’ve found is that there are CEOs who have it stuck in their heads that they want someone with a specific background,” says Linda Havard, who became CFO of Playboy Enterprises after 17 years at oil giant ARCO.

Havard, who recently left Playboy, is “industry-agnostic” in her current search. “I knew nothing about oil or entertainment, but if you come in with the right attitude — that you have to earn people’s respect and roll up your sleeves — it doesn’t really matter,” she says.

Companies may also want to show their muscle within an industry. In general, “the more powerhouse the company is, the less likely they are to go outside their direct niche,” says John Jonas, president of The Jonas Group, which does executive searches for the footwear and fashion industries. “If they’re Nike, they should have their pick from, say, Reebok; it’s unlikely they’re going to pick a supermarket CFO.” And if they do go afield, “the more related the experience, the better.”

That being said, what sets up a finance executive for a shot at a major industry switch?

For starters, experience at a large, multifaceted company known for its training programs appears to be a big boost. New Sunoco CFO Brian MacDonald, for example, spent his early years in GM’s treasury department, working in several different countries on his way up the corporate ladder. Juan Figuereo, who recently joined consumer-products conglomerate Newell Rubbermaid as CFO from beverage maker Cott, spent 15 years at Pepsi in multiple international finance roles and about 4 years at Wal-Mart.

“If a person at a GE or a GM or a Pepsi has had two or three types of jobs, and maybe moved around geographically, that person has already demonstrated a type of flexibility that they can take to the bank,” says Boyle.

It’s also helpful for a prospective leaper to look for nonobvious similarities among different companies. “Think about it in terms of concentric circles — look at sectors that have similarities [to yours] in distribution or supply chains, for example,” advises David Nosal, head of San Francisco–based Nosal Partners.

Framing each assignment as a project — be it executing a particular type of growth strategy or leading a turnaround — can also help. JDA Software, which has publicly announced its intention to grow from $400 million in revenues to $1 billion within the next five years, noted Hathaway’s experience in growing Alliance Waste from a $100 million company to a $6 billion company and the more than 300 acquisitions he’d pulled off in his career in the press release announcing his appointment.

On the flip side, Biggs Porter, who worked in both the defense and utility industries before taking his first permanent CFO role at Tenet Healthcare in 2006, says he was able to cross industry lines in part because he had developed a specialty in cleaning up corporate messes.

Tenet “was absolutely in a turnaround, and if I look at my other companies, they all had some element of challenge,” says Porter. Among other difficult assignments, Porter joined Dallas-based utility TXU just as the company was dealing with deregulation, and became controller at Raytheon in 2003 as the aerospace giant was being investigated by the Securities and Exchange Commission. When Tenet hired Porter, the company was also being investigated by the SEC and still licking its wounds from both hurricane damage and a Department of Justice investigation that ousted its former management team. “If you’ve experienced change and dealt with it in one business, you’re more prepared to do it in the next,” the 55-year-old CFO says.

These days, finance executives may even be able to use the ever-increasing volume of regulation to their sector-switching advantage. Porter says his experience in heavily regulated industries has helped him move, too, even when the rules are different. In such industries, he says, “you have to be able to think along [two] lines at the same time: What makes good business sense, and what will the regulator allow? If you haven’t had that experience before, you’re much more likely to just get frustrated.”

While there is plenty to frustrate finance executives in any industry these days, of course, increasingly they will have to deal with the expectation that they understand the world beyond their own sector. “Companies are realizing that [for executives] to grow up solely in one industry gives [them] a pretty slanted view on global markets, events, and challenges,” says Nosal. “More CEOs and boards are pushing to have candidates with multi-industry, multicompany experiences — not five or six, but two or three where they have been successful. That’s absolutely a feather in somebody’s cap.”