Anand,
I would suggest going through all the recent exit interview questionnaires. If you do not use them, please implement them straight away.
Whilst I agree with most of the suggestions posted by the members above, there is more than meets the eye for a practical problem like this. You may have to do a bit of homework.
Make sure your salaries are on par with the big players.
Ensure the benefit structures are in line with the appraisals, for example, proper increment plans, etc.
Make sure there are enough low-budget employee welfare benefit plans like health insurance, extra holiday buyout plans linked to continuous service, etc.
If interested in implementing the above, you may have to revisit your reward structure. If you discover that the salary/package structure is equivalent to your competitors, the problem could be something else other than remuneration, and you should tread carefully to deal with the crux of the issue, like a problematic/bullying manager, etc. One way of dealing with this is regular (ideally quarterly) employee satisfaction surveys, which could be a confidential survey.
I believe that you don't have to shell out extra bucks to make an employee feel a part of the team. None of the big players out there are going to spend their time celebrating birthdays of the team! I am not contradicting it, but I am not in full support of it either. Remember, you cannot stop a job hopper to whom the grass is always greener on the other side!