UPDATED: 17 February 2011 at 5:30 p.m. to reflect La Quinta franchised locations

Lists are a popular and common feature in many hotel industry publications. Today, I’m going to blow the lid off of all of them by suggesting that the biggest hotel owner is not one you typically see at the top of any list.

First, allow me to delay the big reveal and explain how I arrived at this conclusion. I extend thanks to Adam Kirby (@Askirby on Twitter) and his inspirational tweet that noted room counts shifted the placeholders at the top of industry due to recent earnings statements.

For the record, InterContinental Hotels Group’s owned, managed, franchised, leased or joint-venture 2010 portfolio had 647,161 guestrooms. Marriott International supplanted Wyndham Hotels with 618,104 rooms (compared to Wyndham’s 612,700 rooms).

When I saw these figures, it got me to thinking about a factoid I’ve been saving since November …

Check this out: The Blackstone Group owns, manages, franchises, leases or has joint venture interest in 5,950 hotels with 892,608 rooms as of November 2010. This is what the big brands report in their portfolios, but we don’t see these numbers from Blackstone because, although the parent company is public, most of their holdings reside in private subsidiaries.

Blackstone, of course, owns Hilton Worldwide, La Quinta and Extended Stay America, among others.

But let’s take it a step further. If we take out Hilton and La Quinta franchise locations, Blackstone has direct ownership in approximately 2,459 hotels. We couldn’t come up with another owner that came close to that figure. (If you know of one, please feel free to share with the rest of us in the comments section below.)

Blackstone owns other properties without Hilton brands, so how do they keep competing brands from sharing or poaching information? Conversely, think about the knowledge to which Blackstone has access. With Hilton, La Quinta and Extended Stay America alone (three portfolios that come to mind), the information is enough to boggle the mind. 

Couple this with the fact that Blackstone also owns Travelport, which operates two of the biggest global distribution systems—Galileo and Worldspan—and also GTA.

Furthermore, Travelport Limited owns Orbitz Worldwide. Seriously. 

Here are some other interesting holdings of Blackstone:

• MeriStar Hospitality Corporation
• SeaWorld Parks & Entertainment LLC
• The Weather Channel
• Merlin Entertainments Group Limited (includes Legoland California LLC)

With all of these companies, there has to be some cooperation to be had among them, right? As far as any outsider can tell, they keep things separate among subsidiaries.

While we all discuss how Google and the online travel agencies could be pulling the rug right out from under hoteliers, I wonder if Blackstone’s got anything up its sleeve? That’s not to say Blackstone is a bully—I just question why we haven’t seen more obvious demonstrations of collective bargaining or product development given their impressive travel- and hotel-related holdings.

Notoriously media-shy Blackstone might be holed up in a boardroom thinking about this right now …