Multiple instances writing to the same file corrupts data

Team,

I have a process which receives messages from an websphere MQ and then
marshals the data with Camel bindy into pipe delimited text and then appends
to an already existing text file.

There are two JVMs in which the process is running. When i switch off the
listener in one of the JVMs, the entire process in working fine, but if both
the MQ listeners are running (in two separate servers), the end output i.e
the camel file has few rows corrupted in an intermittent fashion. Not
happens always.

I suspect that there is a problem with two separate servers writing to the
same file. Any ideas how to resolve it ?

Thanks,
Karthik