Try this document editing platform co-ment.com

Kristoforos recommended this to au-eu partnership colleagues, and they've got a free trial with the company. Our colleagues will be testing the system and will submit them their end-users opinion, in exchange they'll use this shared-document system for free for 1 month. The principle is similar to what I was telling during our intranet meeting –a restricted place, where we could place the doc and invite few people to work on it, rather than sending by email and collecting track changes or comments by email and then consolidating. So, could be worth to try for us too, and may be we could incorporate it in the new intranet (co-ment.com ).