The making of Jeff Immelt

Fortune has joined the human resources consulting firm Hewitt Associates and the HR services firm RBL Group to identify companies around the world that are best at attracting, developing, and keeping business leaders.

It's no coincidence that they turn out to be many of the world's top-performing companies. After years of repeating that "people are our most important asset," managers everywhere are discovering that in an information-based economy, it's actually true.

"Our board of directors spends an entire day on how we're developing our top leaders," says J. Randall MacDonald, HR chief at IBM (IBM, Fortune 500), No. 1 in this year's ranking. Despite working for the company most successful at leadership development -- and spending almost $700 million a year on it -- he knows the race never ends: "My lead over the competition is probably one-half of an inch."

There's no better time than a historic recession to push people outside their comfort zone, yet recessions are precisely when some companies cut back on this valuable tool.

Developmental assignments are an investment, so they incur costs before they pay a return. Pulling someone out of a job where he's performing well imposes a cost, and putting him into a job he hasn't yet learned imposes a further one. The payback -- a strong leader -- may not emerge for years.

Truly believing in these professional challenges requires more courage than you may suspect. Consider what happened at General Electric (GE, Fortune 500) back in 1989, when the company's appliance division discovered it had sold a million refrigerators with faulty compressors.

The refrigerators would have to be returned -- the largest appliance recall of all time. To manage such a crisis, most companies would turn to the most experienced "recall" executive on earth. GE did the opposite.

CEO Jack Welch and HR chief Bill Conaty decided to put a promising 33-year-old manager, future CEO Jeff Immelt, in charge of the situation, though he had zero experience with appliances -- or recalls. Welch and Conaty saw an opportunity to build a leader. And while the experience was hellish, Immelt says, "I wouldn't be CEO today if I hadn't had that job."

The best companies tailor these "stretch" assignments to the future business environment, which is why "global" development has become the major theme among virtually all the companies in this ranking.

Many of them -- including P&G (No. 2 on the list), GE (No. 7), Colgate-Palmolive (COLGATE-PALMOLIVE) (No. 12), and PepsiCo (PEP, Fortune 500) (No. 20) -- get most of their revenue from outside their home country. All realize that global expansion holds their greatest growth opportunities and often their greatest challenges. "International assignments are where we generate the most stretch," says Richard McAnally, an HR executive at Deere (No. 14). (via fortune).