Q: One of my co-workers is really hard to work with. He seems ambitious, and sometimes I think he doesn't share information I need in order to make me look bad. What can I do?
A: Focus on your own goal: to do your job well, and look for ways to obtain the resources you need.
The inner game
It seems like the situation may be getting under your skin; the first step is to address that so that you can bring balance to your considerations. Take several deep breaths, breathing in through your nose and releasing through your mouth. Let any stress, annoyance, or anxiety dissipate with each breath.
It seems like there are two issues here, both rooted in mistrust. In general, what is your trust level with this colleague? Are there other ways in which he demonstrates himself to be untrustworthy? Or has he generally been someone you could count on? This could lead you quite deeply into considering what it requires for you to trust someone. If, for example, the fact that he wants to get ahead in his career undermines him with you, you may have to reassess your values. If you have evidence, however, that he would step on people to get there, that's another matter.
Regarding information sharing, are there other ways you could interpret his behavior? He may not actually know what information you need at any given time, or may have other priorities that he sees as more urgent. This doesn't get you the info you need, but it does change the dynamics based on motive.
Then reflect on his interactions with other co-workers. Do others also have issues with him? Also consider your general "get along" skills to ensure that it's not a more-general pattern with you.
The outer game
Map out the information you need: what, when, and from whom. Depending on your work, this may take the form of a monthly plan for ongoing projects, or it may be more general for one-time requests. Notice risks you may have in terms of tight turnaround times for information from others, only having one person who can help you (what happens if someone is sick or on vacation), or major unknowns that could require analysis that isn't built into the timeline.
Then start planning to mitigate these risks. For example, you may have a certain type of project that will require information from this co-worker with only a two-day turnaround. Each time it occurs, it could cause you to feel that information is being withheld, but it could actually just be a planning issue that could be worked out collaboratively in advance.
But you may find that benign explanations don't hold up, and that he really is sabotaging you. At this point, take your concerns, your evidence, and your efforts to effectively collaborate to your boss to get help. Because you've been proactive and collegial, this will not reflect poorly on you, and could gain you the support you need.
The last word
Start with the high ground so that you can resolve the issues or, in a pinch, come out ahead.
What challenges do you face at work? Send your questions to Liz Reyer, a credentialed coach and president of Reyer Coaching & Consulting in Eagan. She can be reached at firstname.lastname@example.org.