Retaining rank when integrating with a larger site

[DenisL]

Our client was just acquired by a larger company and they want to merge their 100-page website into the larger, parent company's 500+ page website.  They currently have a strong ranking for a focused group of keywords and are worried about losing their ranking position for those important keywords.  The keywords are roughly 80-90% of the focus of the old site, but will represent only 30-40% of the focus of the new site.

Will this move hurt their rankings?  What can we advise them to do to retain the value of their current ranking strength for the target keywords?

[EGOL]

Will this move hurt their rankings?

I am not going to guess.

If the larger website is authoritative and powerful this merger could be kickass - like uniting the clans.

However, if the larger website is weak, or spammy, or linking to bad neighborhoods, or inefficient...  the power of the small site could be lost in the (abyss, mess, crap... select appropriate word).

If the larger site is nothing special my guess is that their rankings will drop as linkjuice and authority of the small site seeps into the larger mass of pages.

To be honest... for a given amount of power I prefer to fight with a small compact site rather than a large expansive one.

Bottom line... if the small site belonged to me and was making lots of money I would continue to enjoy it and not take the risk of change - and I would simply link from the large site to the small site to let visitors know that you have another property.  Maybe the larger company has other allies who would be willing to do that too, thus making the small site even more powerful.    

[YannickVeys]

Good tips from EGOL.

How does the bigger site on the keywords that the smaller site ranks for, rank?

If they don't rank for it period.... as in: not in the top 50 for those keywords, it's really no use to redirect the pages. Because probabluy their entire on page optimization is crap. So in the beginning all will be well. Search engines will just give the rankings to the bigger site, but they will drop because the new content and site structure cannot maintain the rankings.

[DenisL]

Very helpful -- gives me some great perspective to start with.  Thanks to both EGOL and Yannick for your responses.