How to consolidate our companies

hey,

i have search many thread but nothing found a good post i want to know that how can we consolidate our company

e,g we have a one Head Office and at least 14+ branches and 3+ subsidiaries which is rotated in different country and region.
we manage our individual accounts very well, now its time to consolidate our accounts that we get data immediately.

is there any way to resolve this problem or

is that this thing we can do that, we create a new company with the name of Company-consolidate
and how can we link this company with all HO, Branches and Subsidiaries it means grab data by CC from all HO etc when anything will be done in these..

regards