FORTUNE -- Dear Annie: I used to love my job, but everything changed after my employer merged with another company. I was transferred to a different department, where my new boss is not really involved in what I do, and my day-to-day duties have become much more limited and routine, despite the fact that, in the past, I always excelled at special projects. In fact, even though I'm highly respected here and have had strong performance reviews, I'm not sure my boss knows what to do with me. Now, performance review time is coming around again. Can you give me any guidance on how to approach that discussion, with an eye toward changing the situation? -- Underutilized Asset
Dear Underutilized: I'd be willing to bet you aren't the only one wondering. The number of U.S. mergers and acquisitions jumped by 23% in July, after a slow first half of the year. That means thousands of people whose jobs survived those mergers (and many, as I'm sure you know, do not) are now trying to figure out how they fit into the new organization.
Make no mistake, a post-merger company is a whole new enterprise. "If you're sitting at the same desk in the same office, it's easy to think that nothing much has really changed," notes Steve Spires, an Atlanta managing director at human resources consultants BPI Group. "But in fact, and especially if yours was the acquired entity, you're now working for a different company, just as if you'd gone out and gotten a new job somewhere else."
In a way, it's an even bigger adjustment, because new hires can usually trust that their bosses have at least a passing familiarity with their resumes. You, however, can't assume any such thing. "Is your new boss aware that you used to excel at special projects?" asks Spires, who has advised plenty of post-merger organizations and has seen firsthand where the pitfalls lie. "Managers usually have so much on their plates that they just don't have time to research your background and experience and understand what value you can add. So it's up to you to step up to the plate and tell them."
Your upcoming performance review is a perfect chance to do this. "We usually recommend that employees approach this kind of conversation in three steps. First, look around and figure out what the new, combined company values and expects," Spires says. "Then, think of some ways that you could help provide what's needed. What skills and experience do you have that your new boss probably doesn't know about but might be able to use? And third, talk it over with your boss. Describe how you see yourself contributing, and ask whether he or she agrees."
Spires recommends that, since you miss the special projects you used to do, you might prepare for the meeting by spotting one or two that you could tackle now. "Identify a need, and then be ready with specific examples of how you handled similar projects in the past," he says.
What if your offer to take on new challenges falls on deaf ears? For starters, look around elsewhere in the company for projects you might be able to help with, suggests Dan Schawbel, who is managing partner of research and consulting firm Millennial Branding and author of Promote Yourself: The New Rules for Career Success. If there aren't any, go to Plan B: "Anyone who isn't using their talents at work needs to create a strong online presence," he says. "Start your own website to showcase your achievements, and get active on LinkedIn and Twitter. If you get your name out there and highlight your skills, the employers who want what you can do will be able to find you."
First, though, talk with your boss. Expanding your current role "may well take more than just one discussion," says Steve Spires. "Your performance review is an opportunity to start the dialogue, but it should continue as time goes on." He notes that he's come across many employees in your position who hesitate to try changing the status quo. "On a bell curve of assertiveness, most people are somewhere in the middle," he says. "So, often, speaking up is hard work." Even so, if the conversation eventually leads to your liking your job as much as you did before the merger, it'll be worth the effort.
Talkback: If your job survived a merger or acquisition, how did it change afterward? Did you find the adjustment difficult? Leave a comment below.
New bosses, different rules, uncertain expectations -- when your company is acquired, the only sure thing is that your job is on the line. Here's how to come out on top.
By Anne Fisher, contributor
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