Ms. Rudd, now an executive-search consultant at I-Search Ltd. in London, had found mentors a valuable source of advice several times in her career: when she moved from a senior corporate finance position to become director of a venture-capital company, and when she left that post to start an online share-dealing business.

"If you want a career change, you need someone from the other side to pull you in," she says. "Going into a career which is very networking-based, you need those relationships even more."

Like their male peers, senior businesswomen often benefit from the advice and attention of mentors who take an interest in their careers. Those relationships are even more important in a shaky job market, employers and executives say.

Taking Control

While networking is an accepted corporate buzzword, mentoring is just starting to take off in Europe; formal corporate programs remain rare. In the long run, as full-scale transitions to new careers become more common, informal ties may be most valuable, executives and experts say.

"It's about taking control of your own career," says Lucy Marcus, chief executive of Marcus Venture Consulting, which advises private-equity houses, and founder of HighTech Women, an online and offline networking group for women in tech-related sectors. "You can't expect that the company will do it for you, because companies don't mean what they used to."

Building long-term professional relationships outside the office has several advantages, Ms. Marcus says. Such informal relationships avoid the internal competition and conflicts of interest that can come with in-house mentors. They allow women to freely express uncertainties they might be unwilling to display in their own workplace, for fear of being viewed as weak. And mentor and protege can bond across sectors and, in some cases, long distances. "You can see role models from all over the world that you can draw on," Ms. Marcus says.

Broad Approach Urged

No firm statistics exist, but the number of dedicated in-house mentoring programs across Europe is limited at best. Although larger companies, such as Microsoft Corp., Deloitte Touche Tohmatsu and Deutsche Bank AG, have launched mentoring plans, they are in the minority. But increasingly, experts say, the companies that want to attract the best clients will see a supportive working environment with happy employees as a competitive advantage. And that means fostering mentoring relationships, from entry level to senior management.

"The people who want to progress in their careers want mentoring to be endemic within a business," says Larry Hochman, a former director of people and culture at British Airways' Air Miles unit who currently runs a speaking, mentoring and consulting business in Venice. "It has to be driven down the hierarchy" to allow employees at all levels to take advantage of it, he says.

Companies that identify mentoring as a part of their business strategy are most likely to create successful programs. But many still don't see it as part of a broader approach to cultivating and retaining talented women executives, says Avivah Wittenberg-Cox, a career coach at the Insead business school in Fontainebleau, France, and president and founder of the Paris Professional Women's Network.

Mentoring programs for women are only effective as part of larger corporate-wide gender-diversity efforts, she says, and many companies still fall short in that area. With senior women thin on the ground at most European companies, Ms. Wittenberg-Cox says, a better approach is to form external networks for mentoring, sharing top executives from a number of member companies.

Deutsche Bank Programs

Deutsche Bank has integrated several of these approaches. It runs formal mentoring programs that give rising women executives access to its senior managers, as well as employee-initiated grass-roots networks that allow groups of junior women to learn from a senior woman.

More than 400 employees are active in the bank's programs in New York and Frankfurt, and it is adding a program in the London office, says Mona Lau, global head of diversity at Deutsche Bank. She favors peer mentoring programs for their flexibility, and says they are more useful for women below senior management; women in these programs are exposed to a variety of mentors and learn from each other as well.

Deutsche Bank also has participated in cross-sectoral programs with other German companies, such as Lufthansa. "As times are tough, there are more gray areas where people need some guidance," says Ms. Lau. "This is where someone who is out of the direct business line and has different experiences can really give you some coaching."

Talking Things Through

Professional relationships that have developed naturally are often the most rewarding, women say. "What you want is someone outside your direct field and yet someone who has an understanding of what you want," says Ms. Rudd, the headhunter. "It has to be something that goes quite deep."

She found Lucy Marcus, a longtime business contact, to be particularly helpful. "I had a number of ideas, some of them very different and radical, and really needed to talk them through with someone who understood my skills, weaknesses and character," she said. "She helped me clarify what the alternatives were and how best to assess the risks of the various options, and helped me evaluate what level of risk and commitment I was willing to take on, given that I was still handling the close-down of my [Internet] business."

The best mentoring relationships develop naturally and can't be created by fiat, Ms. Rudd says, adding that formal mentoring programs, by contrast, are "more akin to having a tutor at university."

A Formal Success

But at least one innovative program in Scandinavia has shown that such a formal system can produce results.

Hilde Myrberg, vice president of power sourcing and marketing at Norwegian energy giant Norsk Hydro, participated in one such exercise for an 18-month period. The program uses detailed psychological evaluations to match businesswomen with senior mentors from the public and private sectors.

Ms. Myrberg, who was a corporate lawyer with Norsk Hydro at the start of the program, says meetings with her mentor, the chief executive of Norway's largest daily newspaper, helped convince her to leave the safer track of the legal profession and move into management.

"I was hesitant to make that step," she says. "He gave me the confidence that I could do this too, and made me familiar with the decisions that I had to take." Shortly after the program ended, she received her first offer for a management position in business development.