'But I deserved that promotion!'

(Fortune) -- Dear Annie: I'm so frustrated I could scream. I'm a production manager for a large, well-known company that has a stated policy of promoting from within whenever possible. Internal job openings are posted on the corporate intranet site before they're advertised elsewhere, and our bosses are always encouraging us to "aim high." Yet twice in the past three years (most recently just yesterday) a candidate from outside the company beat me out for a promotion. I've been here for 12 years, my performance evaluations are excellent, and I'm more than qualified to move up. Why do they keep doing this? Should I start looking elsewhere? -Taken for Granted in Tacoma

Dear Taken: It's doubtless no consolation, but recruiting-industry research shows that, when competing against outsiders for a bigger job, only about one-third of internal candidates win. John Salveson, a principal at headhunting firm Salveson Stetson Group (www.ssgsearch.com) says there are several reasons why companies launch external searches even when they have strong candidates already on the payroll.

The company may be trying to acquire skills the organization lacks, he says. Or they may want to bring a new perspective and fresh thinking - even from a different industry - into the fold. Hiring outsiders also "sends a message to internal candidates that they are competing against the best available talent, from both inside and outside."

What can you do about it? Sally Stetson, Salveson's co-founder and partner, notes that current employees often don't compete aggressively enough. "Internal contenders for a bigger job shouldn't assume their colleagues and higher-ups know everything about their background and experience," she says. "You need to sell yourself to those making the hiring decision, and send a strong message that you're ambitious and interested in moving up."

Let's say you've already done that - twice now - and they still chose someone from outside. One possibility is that whoever has been giving you those glowing performance reviews hasn't been entirely honest with you. Managers are notoriously reluctant to deliver bad news, to the point where many of them never give detailed performance reviews at all. So, if you want to know why you keep getting passed over, you may have to press for answers on what the outside candidate has that you don't, and what you can do to improve your chances next time.

Part of the responsibility lies with the people doing the hiring, Stetson says: "Companies need to be sensitive to current employees competing for a position. If they're treated badly and kept in the dark, it may encourage them to start job hunting."

In the end, that may be your best bet. After 12 years with this company, your perception that they take you for granted is probably accurate. Sometimes, if you really want to move up, you've got to move on.

Have you ever been passed over for a promotion you deserved? What did you do about it? Post your thoughts on the Ask Annie blog.

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