Using iWork Pages you can simply re-save your PAGES documents as TXT files. If you are not Mac user, you will need to use some online document conversion service like ZAMZAR to do the job.
Convert Pages document to Simple text.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert pages to txt on Windows
A simple converter for iWorks Pages documents
Convert from pages file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.