Word does not really have the ability to perform a "multiple items per
condition (=key field)" mailmerge.
See the "Multiple items per condition" item under the "Special merges"
section of fellow MVP Cindy Meister's website at
http://homepage.swissonline.ch/cindymeister/MergFram.htm
Or take a look at the following Knowledge Base Article
How to Work Around Duplicate Names in Mail Merge Data
http://support.microsoft.com/default.aspx?scid=kb;en-us;302665
However, as the data is in Access, I would use a report in Access to do what
you want with the company details as a group and the holders of the catalog
in the details.

Signature
Hope this helps.
Please reply to the newsgroup unless you wish to avail yourself of my
services on a paid consulting basis.
Doug Robbins - Word MVP
>I am writing a letter in Word and using an Access database for the data
> input. The database is a list of people within companies that have
[quoted text clipped - 7 lines]
> list
> could be from one to 20 people. Is this possible?